Ah, but he doesn't know how to befriend others. He never befriended Fluttershy, she chose to be his friend out of neccessitity. It worked, yes, but the fact remains he didn't really learn anything other than having a friend isn't so bad, but it's not mandatory for him still. During the entire ordeal, he was making sure no other pony could ever seal him back up.
I fail to see your point?
What's wrong with coming up with theories on something I enjoy? *lowers his sunglasses* I mean, I did the same with Pinkie Pie during Season 1 and that's how I wrote "Going Home" for Equestria Daily. Theories are fun and they don't need to make sense for as we all know...