Well first off I'd say stereotypes are bullcrap. They exist for a reason, but those reasons are almost always such an oversimplification that they draw the wrong conclusions. But I'll play along...

There's always a certain amount of crap handed down from one generation to the next. It's cheap, and self rewarding. Boomers have been given crap continuously since the beginning, by the previous generation, their own ranks (it's a highly varied generation), and generation X. Now that their biggest critics are dying off, they're feeling encouraged to dole this criticism out themselves. They know better than to do it to generation X, because Xers (I'm an Xer) are nearly tone deaf due to the incessant whining by boomers. Plus, boomers are actually starting to go deaf so they yell a lot more than they used to. So they're skipping us over and going straight for the millenials.

My advice is to take it like simple teasing rather than taking it seriously. The boomers' bark is worse than the bite.

I like millenials. They've got a relatively decent balance of idealism and reality check. My only complaints are they spend way too goddamn much of their income, as a percentage, on housing and foo foo bar drinks.