Well, there are something like 3 000 000 kids in the US who play D&D, so of course there're gonna be some freakshows. And on LSD...my god, how can you possibly try and pin that on D&D?
People who stereotype D&D have never played it...trust me, the last thing you'd think of one of me and my friend's campaigns is nerdy. Dirty, disgusting, wrong, yes, but not nerdy.