[hollerith]

Because your wife' brother's experience shows that tabooing a word doesn't prevent bullies from using the word. Or was his experience before 1990?

[mlyle]

Right around 1990, and I don't think the "really, don't say 'retard'" thing took strong effect until early 2000's.

Our culture's imperfect, but there's a fair bit of evidence that it's a kinder, more courteous world-- especially for youth-- than 30 years ago. Taking some sharp edges off language may have helped with that.