Yes, it is really that bad. Jackman, Liev Schreiber, and Ryan Reynolds are all really good, but the rest is a mess:
-Lots of mutants that have no reason to be there besides fanservice. The glorified cameo that is Gambit being the most egregious of these, followed by "why is Cyclops even in this movie?"
-Cyclops's optic blasts AREN'T HEAT VISION movie. ALL of the other films got this right, so why couldn't you?
-The special effects were shockingly bad in places given the amount of money spent on it.
-Baraka-pool, that is all that needs to be said about that.
-Wolverine looks like an idiot throughout by falling for such an obvious trap/set-up.
-The explanation for the "Wolverine" moniker is incredibly lame and for all of the talk about "that other half" or "unleashing the animal within," etc, he never comes across like an animal in the film. In fact, he's pretty much the nicest most moral guy there, which negates the whole point.
-There's no attempt to keep the continuity with the other films. Which is even more pathetic since all they had to do was watch ONE other film, X2, and line it up with the flashbacks. But they couldn't even be bothered to do that.
-Stryker's plan makes no sense, and he's nowhere near as interesting or menacing a villain as he was in X2.
-Xavier looked more like an egg than a man with all the CGI done on his face.
-Etc.
But worst of all, they squandered a great and compelling story. Also, the little montage that we get in the opening credits of Logan and Victor fighting in various wars across history. That seems like it'd be a FAR more compelling movie than we actually got, yet it's shoved into a five-minute montage. Heck Logan's time as part of Stryker's team seems like it'd be a far more interesting movie than what we got as well.
It was tremendously disappointing all-around imo.