I don't think I've used the word once since high school. Had it been generally unacceptable back then, I wouldn't have done so. I graduated high school in 2004, and it was at least an acceptable insult back then (though not to call a disabled person), I think. I was a jackass in high school, though, so I could be wrong.
Either way, it offends people now, so we shouldn't say it. It's that simple. Deliberately offending people just makes you an asshole.
I think saying it was acceptable is a stretch. I agree it was certainly more commonplace and more acceptable than now, but it was still criticized a good bit.
You're absolutely right. I meant it was "acceptable" -- I don't recall hearing people judged for saying it, but that was among an immature, high school crowd. It was definitely considered offensive to use as a label, rather than an insult (which was on the same level as f*g; not acceptable, but commonplace).