What's the worst thing to happen to hip-hop?

Eminem.

I feel bad saying that because Slim Shady LP was very good, Marshall
Mathers LP is in my all-time top 10, and Eminem Show was very good.
BUT he (unintentionally) brought a huge fan-base into hip-hop that
never should've been brought in, and he set the rhyme-structuring bar
too high; most up-and-coming MC's had to put all of their effort into
just trying to keep up technicaly and this has come at the price of
having the substance/soul sucked out of their music. At his best
Eminem was the most impressive MC (not necessarily the BEST, but the
most IMPRESSIVE) but I think hip-hop overall would be better if he had
never come into the game.
@matty D
But I'm saying it's a combination of him being very good AND appealing
to kids who probably would've never been into hip hop otherwise. I'm
not saying that he is single-handedly to blame, just that he did a lot
more harm than good EVEN THOUGH his only intent was to be one of the
best.
@mic messiah
HUH?!? You could make the argument that Doom is better ARTISTICALLY,
but TECHNICALLY he is not even close.