For me it's never been that I'm against change or risque humor. It's that it used to be more subtle and adult. That's why I liked the Muppets, even as a kid. And I don't think it's necessarily true that the younger fans prefer the more recent projects. But I do think the older projects are lacking exposure.
I get that and second it. The Muppets do themselves a disservice when they try too hard. I feel Steve's Kermit used to do that (the "way to get down with your bad selves" MFS line and some TV appearances), but now he's settled in nicely.
The Rizzo "Girls Gone Wild" comment on Oz was terrible on many levels and not even funny. However, Gonzo's nipple comment was creepy, but funny IMHO. It was an unintentional mistake by Pepe. Kelly Osbourne (although cut from TV version) appearance was trying too hard. It's just how it goes.
On Muppets Tonight I remember the out-takes being the best parts. I wish some of that spontaneity could be utilized in the productions. Muppeteers are sharp people...er...Muppets...er...Muppetpeople!
The main issue I have with the Muppet Christmas Special was that anytime a song or something interesting started flowing it was cut-off in a way that said the very things I love the Muppets for are no longer valid in contemporary entertainment. I'd rather have seen the entire Moulin Scrooge number and the Muppet Theater's line-up of performances. Heck, why didn't they have Suggs with some red and green Muppephones? The movie had enough to entertain me in other ways, but there was so much Muppet gold that was discarded.
That's what I feel was missing. The charm, music and vivid color of the Muppets.