Thanks for the answers.
I neverhad a problem with the essentialists and Worf's bahavior per se.
I never thought the essentialists had any real message, that they were just some jerks spouting nonsense and most Feddies wouldn't even know what they are talking about.
They are just there to annoy people, their agenda is bullshit.
And there comes Worf. He is severely pissed, he's completely out of control, acting stupid to the extreme. He sides with those essentialist because he totally lost perspective.
and the environment makes it even worse. The least "controlled" environment available, and Worf thinks he's the one "true" Federation officer, an identity which he always thought he could merge with his Klingon values.
It wouldn't be the only serious flaw we encountered with Worf and his "double identity". He just allows himself too much to endulge in Klingon behiavior, even if it completely contradicts orders and adequate "Fed" thinking ("Rules of Engagement" for example). And here he already knows it won't get him in trouble, so he acts like a dick, hiding behind his Starfleet uniform and rank- and makes his own little Klingon opera.
For him, being the dude he is, in this emotional state and with this environment, it kinda made sense...and it was nice to see more of Risa than in the episode with Picard.