"I've seen a lot of backstories written about how Equestria is simply a post-apocalyptic Earth set in the distant future. I decided to expand on it in a much less... grimdark fashion."
These quotes from Twilight Sparkle in the original story were meant to be joking, but became way less funny with the numerous stories that have the barrier being intentionally expanded as a means to force ponification, and any stories that have the PER in them.
"Now, I'm almost positive all of you are here because you want to become a pony. This is a fact. You don't come here because you don't want to be a pony, unless someone forced you at gunpoint, but that's a different story."
"Our plan is to ponify you, the sooner the better. Expect this to happen when you least expect it."