@Felthry Flathead use I've always associated with "easy, works, doesn't strip" and anything else has been more of a "liable to strip, extra expense to be able to try at all, looking up charts and things to make sure you're using the exact right size, issues with my less-than-great dexterity, making mistakes that ruin things"
But I'm also not a big tools-related-stuff person and that's probably a lot of it.