Very first post. I couldn't help but sign up and comment after seeing such a discussion.
I'm going to take the ballpark guess and say this topic was MAINLY brought up by Yahtzee's comment of MGS4's attitude towards gameplay elements (there's more to it than that, obviously, otherwise people wouldn't get so angry about it). And I kinda have to say... well. Most people just get it wrong and use it as a blanket term for other cases such as OCD or ADD. (That having been said, I don't know /enough/ about the other cases to really say anything about which terms are "wrong" and which ones are "right.") I can't completely say I blame people for using "autistic" as the basic term, since autism in and of itself /is/ a blanket term. Big deal.
That said, it usually annoys me a little hearing someone use such a term like that, but the same can be said for when people blast blacks, whites, Asians, gays, straights, lesbians, Catholics, Muslims, atheists, males, females or pretty much any ethnic, religious, or whatever "sub-race" that can be found on the planet. Sometimes it just feels hateful, especially when you aren't in the best of moods yourself.
On the other hand, where the bloody hell would we be if we didn't have any sense of humor? If you can't laugh at yourself, why can you see it as kosher when someone else gets laughed at? Because, in your experience, you find that YOUR group gets made fun of more? The only reason it seems that way in many cases is because you're too busy fuming about someone's "personal attack on you" to notice that it happens to everyone. (Sorry, that gets on my nerves more than other things.)
Not all of the insults are warranted, of course, and some are done with true malice, but, think about it. If someone couldn't make fun of you for being autistic, they'd make fun of you for being gay. If it wasn't for being gay, it'd be for being Catholic. If it wasn't for being Catholic, you'd be blasted for being a heathen. In those cases it's just the insult itself, not what the target weak point is.
Most of what we see, though (like, say, Yahtzee's Asperger's Syndrome comment in the MGS4 review), is done in a more playful manner. During those times, you're better off taking the joke at face value and assuming it wasn't meant for anyone to be offended. To quote MGS2 (ironically), "There are some things you just have to pass on. The trick is knowing which ones."
...Whew, that was long, and I probably contradicted myself. Thanks for reading if you bothered. Nitpick and proofread for me as needed.
(Edit: For example, my complete and utter failure to miss the word "self-diagnosed." Oops. That probably killed half my argument.)