It's not so much a circlejerk as much as a knowledge that KDE plasma is the most approachable DE with the most polished first experience for the majority of new users
You say that like it's a fact rather than just your personal opinion.
The reason it gets interpreted as Gnome bad
No no no. I'm not misunderstanding people liking or preferring Plasma as hating Gnome. I love Plasma, and so should most people, it's a very good DE. I pretty much only use Gnome and Plasma these days, and can happily praise or criticise either of them.
People do have a hateful circlejerk about Gnome. Look at any large discussion about Gnome and it gets full of haters who still can't accept that Gnome 3 went in a very different direction to the traditional WinUX. People that say it's shit. People that accuse the devs of being evil. Go onto a submission about a new Gnome release and you'll find some smoothbrain making the classic wHaT fEaTuReS DiD tHeY rEmOVe tHiS TiMe joke which holds zero basis in reality.
And I'm not talking about fair criticisms either. I could rattle some off the top of my head. I'm talking about hatred.
Shitting on Gnome very much is the hip, trendy thing to do in the Reddit/Lemmy/reactionary YouTuber space.
According to many in the Linux community, Linux is all about choice, so long as your choice is the same as theirs.