I think there is a misunderstanding here.

The problem with this review isn't simply that it isn't a glowing positive review. Of course everybody has a right to state their honest opinion, and of course some Phish shows are better than others. They can't all be 5 stars. Most reasonable fans agree with all that. That's not the problem.

The problem is that the author seems to embody a certain kind of entitled douchebag vet in an almost Platonic sense, as if he were The Jaded Vet in archetype form. Most fans don't like that guy, and when you play that character to the hilt the way this guy did in this review, people are going to react in a strong way.

Short version: Even if you didn't like the show, you don't have to be such a dick about it.