I was expecting this thread to show me why Twilicorn was so hated in a very objective way and I ended up being disappointed.
I could not find a reason why Twilight Sparkle as a princess is not good, other than applying a HUGE (wings) change (that still we haven't seen in action yet) to a character that we all know about.
You said that you lost a "connection" with her. We only got to see her as an alicorn for at least 5 minutes of the MMC episode, and even still I felt like she was the same Twilight Sparkle that we all know. "Is there a book about being a princess that I should read?" that line is SO Twilight Sparkle and even with the wings and the slightly elongated torso, she is the same Twilight.
Now you mention, why the change? why? sadly... most of the reasons is money, Hasbro only wants to merchandise their products and they need an incentive to sell better the new Princess Twilight Sparkle, but is change always bad? no, is not, and I feel like the writers nailed it cuz Princess Celestia was hinting since episode 1 that Twilight was closer to be "ready"...
I think there is not a single soul that hated the moment when Goku got transformed into super saiyan for the very first time in Dragon Ball Z, then, I say, why hate this? can you be so selfish and uptight that you won't tolerate this character to experience growth and continuity, do you want Twilight to be stuck in the same loop over and over again, her personality will always be the same.
And as you said it, about your depression, I MUST agree, it was rather pathetic on your part to get depressed over this, I can understand the special bonds that we have with our favorites ponies, but this was just too much, especially because Twilicorn hasn't been explored or exploited at all. I repeat she only had wings for 5 minutes.
You just jumped into conlusions too fast.
What can I say I don't agree with any single thing you said, in fact it's unrelated and blaming her because you got depressed on your own, it's just ....hmmm...I have no words, this would be better for a blog entry because I feel like the there's no need to discuss much things about Twilicorn over here