I have to admit, while I do like the direction they were going to go eventually that we've seen in 3 of the 4 last episodes, I'm skeptical about what they're saying here.
About the "mean spirited" thing. That went away a few episodes in. The first episode had that completely awkward scene with Scooter and Banks kicking each other out of the golf cart. That and a few of the more adult jokes going away has made the series better.
And while I do agree Piggy did have her characterization go a bit too far early on, at least she was given the excuse of going through the biggest lows of her life. I do not see why this is completely foreign to the character, especially since Frank Oz's interpretation of a character that had a miserable home life and ran away to stardom, adopting a massive ego as an act. I don't see why this little addition to character development is seen as a bad thing, especially since I feel it could lead to a very satisfying payoff. Especially since Walk the Swine gave us that nice moment of her passive aggressive, one upping apology. Not to mention how the past few episodes softened her up and made her more vulnerable. And I'd take selfish, egotistical Piggy over a lobotomized "Kissy Kissy" Piggy anyday. Heck, Piggy was meaner in Muppet Babies overall than here.
But the complaint I don't get is frustrated, shell shocked Kermit. I heard the same complaints about him in The Muppets, when he was defeated and depressed without Piggy and the rest. I see parallels between that here. What I don't like is happy-go-lucky, Mickey Mouse but a frog, only positive emotions Kermit. We had a problem with that in the 00's, and I don't think Steve's to blame. I like Kermit going off and screaming about how he wants his KERMIT THE FRO-O-O-O-O-O-O-OG T-SHIRT!!!! His outbursts of both not wanting to have never been born and wanting to be born. His KNOCK IT OFF WITH THE KNOCKING IT OFF!!!! And I also want to see his calmer, quieter moments as contrast. The did that beautifully with Pigs in a Blackout. If they can keep that up and not give us constantly smiling Kermit from MFS (you're friend is having an existential crisis, he's being cut up in a science lab, and you're freaking house painting?!?!), I'm sure the audience can be happy.
Now, elements of the original show and more wackiness I'll admit are what this show needed. Not at the expense of the format, mind you, but one that gels perfectly with it. That can be done, as the past few episodes have proved. The giant stick of butter in Pigs in a Blackout alone. I still want to see Kermit and Piggy struggle at realizing they need each other and they made a mistake (the breakthrough in the last episode felt all the more satisfying as a result), and I still want to see Fozzie and Becky brought up from time to time. Just no Gonzo on a blind date or Scooter dating a meh celebrity again. But if it turns into the Happy Sesame Street Muppet Babies Smiletime Hour, (or even season 1 Muppets Tonight), I'll be disappointed. The Muppets needed a format change and for better or worse, that's what we got. They can change the show into something more Muppety without sacrificing what they built up to, and hopefully that's what's going to happen.