How come no one ever says 'Yo Momma' jokes any more?

[Indrid Cold]

In the 90's, 'Yo Momma' jokes felt so fresh and original, everybody loved them. I remember watching White Men Can't Jump with some pals, and it was like our generation's Sex Pistols. "Yo Momma's so such-and-such, she's such-and-such". Possibly the most famous example was "Yo momma so fat, when she's walking around the house, she's walking around the house" (makes gesture of amorphous blob encompassing entire house)

What's happened? Is everyone just too polite now? Maybe our mommas are so ANODYNE nowadays, it's ridiculous to make any insinuations about them?

I'm wracking my brains here.

TWS: Yo Momma is so pleasant, when she wears an apron, it's got 'World's Best Mom' on it, not because that's what's printed on it: God makes the words just materialize there.

See? Rubbish.