To be fair, a lot of them included phrases like "never sailing the Wish again", "one and done", "total failure", and so on. And a bunch of other "reviews" were just copy/pasted from Facebook or somewhere else. I've seen a very small number of well-reasoned, thoughtful reviews posted here and they seem to all find good and bad things about the ship, as you'd expect. But a lot of the negative reviews are just parroting what they read somewhere else, including factually incorrect statements.
I'm sure that there are plenty of things to criticize. For example, the service seems to be a bit lacking, probably because of so many new hires and because everyone's getting used to the new ship. Aladdin wasn't ready on time.
Castaway Club members can't get Palo reservations because there are so many concierge staterooms. Etc.
And certainly, Disney can't please everyone. Some people might like the new spread our bars while others preferred having them clustered together. Some might not like the lack of a running track while others are excited to stand on the deck 6 prow. I'm not into high-end jewelry stores and I think that they're a terrible waste of space, but I bet that some other folks absolutely love them and would be sad to see them go. And so on.
I think that it's OK to talk about what you liked and what you didn't like, but I think it's silly to say something like "total fail" or "this ship is only good for kids". Saying "terrific' without really explaining why isn't very helpful either, though.