OK, here is the announcement I have to make:
I will not participate in any more discussions about the worthiness or unworthiness of Twilight Sparkle's Ascension.
The reason is because after three years, it is evident that my position on the matter won't change and Nikki's/RC's and whomever else's opinion won't change either, so there is no point in discussing this matter any further.
But before I close this matter, I want to state my final statement on this matter (warning: I will be using One Piece as a comparison point a lot, so if you don't like that manga/anime, I apologize):
Alicorn Princess TwilightI am honest in saying that when the ascension originally happened, I was not happy with it. In hindsight, I think that was more due to the fact that this was probably the event that brought our group the closest to self-destruct and it made me sad to see a long-time member of our group like R.C. Dangerously leave. I held that unfairly to this episode which led to my not particularly liking this one at first.
But over the years with Twilight becoming my favorite character and the two seasons that followed, I have grown to accept and even love this new development because it allowed the show to develop in a direction that it could add more seasons.
As far as the criticism of Alicorn Princess Twilight goes:
A) EQUALITY
One criticism applied to this ascension is that it disrupts the equality of the mane cast who used to be 2 unicorns, 2 pegasi and 2 earth ponies as well as ponies who were on equal footing socially.
I never saw it that way. This might be a point if the show started in Ponyville where we got to see the events of the Summer Sun Celebration from all six ponies's perspectives and if Twilight's position was that of the local Ponyville librarian.
But the show started with Twilight who was firmly established as the student of the (at the time) sole ruler of Equestria, we got to know the other mane cast members through Twilight's POV one by one and Twilight was also the one to find their connection in being the elements of harmony. So from the very first 2-parter, it was evident to me that Twilight was the primary protagonist with the others fulfilling a secondary protagonist role.
This is not a bad thing as some of the bronies might lead to believe. One Piece has a firmly established main protagonist with Monkey D. Luffy with the other members of his Strawhat Crew being the secondary protagonists. While Luffy's goal of being the pirate king is the main point of the show, the others have goals as well they want to reach and we get plenty of time with them to get to know and care about them.
And this is also what MLP is good at. Each of the other mane cast members has motivations and goals they want to reach, though unlike the Straw Hat Crew, some of them have reached their goal in life. Fluttershy seems content being an animal caretaker in her small cottage, Applejack is busy with her farm and Pinkie is happy to spread joy and laughter throughout Ponyville while baking treats at Sugarcube Corner. But even then their motivations and characters when encountered with situations out of their comfort zone lets us empathize and enjoy their exploits. And aside from Twilight, we have Rarity and Rainbow Dash who still have to achieve their dreams and whom we see coming closer and closer to that goal.
Another point in this regard is Season 2 where the main overarching plot arc was that every mane cast member could now write a friendship lesson and this is meant as a proof that they are now equal. I consider it more as just that: the overarching plot arc for Season 2, nothing more. There are stretches in One Piece where we follow the other Strawhat Pirates with their exploits (be it battles or other hardships they encounter) while we don't get to see Luffy at all. This does not however change the fact that Luffy is the primary antagonist just as the "everypony in the mane cast can now write to the princess" means that Twilight is not the primary protagonist anymore.
The Season 3 opener firmly established that the season's overarching plot would revolve around Twilight as can also be seen by the friendship letters being phased out and also the subtle things that I only noticed this time around (besides "The Crystal Empire" and "Magic Duel", we hear about Twilight having to learn some spells Celestia sent her in "Wonderbolt Academy", Celestia sending Twilight some books to read over the course of the weekend in "Spike At Your Service" and Twilight learning a calming technique that causes her to not worry so much anymore in "Games Ponies Play"). In that regard, Season 3 treated its plot arc more subtle than the other seasons.
B) ROLE OF TWILIGHT'S FRIENDS
Another complaint about Twilight's ascension is that it reduces Twilight's friends to background ponies, the show being now "Princess Twilight Sparkle and her five useless serfs" etc..
The season 3 finale had a really nice quote which sums up the role of the other mane cast members quite nicely:
Twilight Sparkle: "And they mean more than anything in the world to me. My friends..."
It kinda reminds me of this scene from One Piece which made me cry when I first saw it...
(made me also think that if MLP ever did a season-long Impel Down/Marineford Arc, that would be what would bring a brony army to take their torches and pitchforks to Hasbro. If you want to know about this arc, feel free to ask me)
Despite the Strawhat Crew not being primary protagonists like Luffy, they are still given a large spotlight and they are given important roles in the narrative just like the other mane cast members have.
After the ascension, the mane cast continued to be treated as important characters by being challenged in the meaning of their element which led to them discovering their keys, helping Twilight defeat Tirek with their combined Rainbow Power, being part of the Council Of Friendship, having their own Friendship Missions the map sends to as well as numerous other episodes which let us see their own conflicts and their own pursuing of their dreams (Rainbow Dash taking a test for the Wonderbolt Reserve, Rarity taking part in a fashion show in Manehattan etc.).
Even through all that, bronies still think they are as important as Yamcha in Dragonball is to Goku which is just sad seemingly completely ignoring what happened in Season 4 + 5.
C) TWILIGHT'S WORTHINESS
"What makes Twilight such an expert on friendship that she is deemed worthy of being the Princess Of Friendship?"
I would say her stay in Ponyville and the experiences she made and shared with her other friends which was condensed in "Celestia's Ballad" made her not an "expert" but somepony who learned the essence of the importance of friendship (something that even came up in the Season 5 finale).
But even then it is clearly shown that a Princess Of Friendship would be nothing without friends to guide her in matters that she does not yet fully grasp as Celestia herself said: "What would the princess of friendship be without her friends?"
Friendship is something that goes both ways and in which no one or nopony alone can ever be an expert: it takes two ponies to form a friendship. Twilight Sparkle has been crowned the Princess Of Friendship by virtue of the experiences and actions she has made with her friends, but that does not mean she is an all-knowing entity that can decide on friendship matters on her own. That's what the Circle Of Friends is for.
And strange that I never hear anybody complain about Princess Cadance's ascension to the throne of the Crystal Empire. What makes her an expert in the Crystal Empire that she can rule over it despite only Luna and Celestia knowing about its existence? (not to be taken seriously).
So...yeah, this is my final statement on the matter before I close this discussion from my side forever. If my onee-sama/RC or somebody else wants to do a closing statement of their own, they are free to do so.
And one more thing: This does not mean Lapis has to die. He can still be around because I like him, but I will talk other matters with him.
Thank you for your time, everypony.