Well, to be fair, I don't think "magically being removed from our worlds and taken to another inhabited by ponies" was ever something we needed to evolve for.

And actually, these hooves are a little more useful with holding things than you'd think would be possible without thumbs.

[She takes a moment to demonstrate by holding up a book, her two fore hooves wrapped around the book like fingers would be.]

It takes some getting used to, and it's a little harder to hold some things than others. But it's pretty doable.