There's a much wider range of ability among self-proclaimed self-taught programmers. Some may be "self-taught" to the level that they have completed and understood the entire Art of Computer Programming (those released already, anyway). Some may be "self-taught" to the level that they can write a couple for loops in PHP and Javascript.
It's a hard question to answer because "self-taught" spans too wide a range of skill.
I agree with your point of view, but TAOCP isn't really a work to be completed, and I'm willing to wager that anybody who says they have completed it flipped through it and put it back on the shelf.
It's a hard question to answer because "self-taught" spans too wide a range of skill.