I don't watch many movies these days, maybe 4-6 live action movies per year (if even that) as a guesstimate, mostly just animu.
It had cool mechs and monsters, that does not excuse the characters, the dialogue, the acting, the pacing. Even I can derive enjoyment from the movie at times, but if I were to go further and say it's worth watching, worth paying to see, or even 'good' as a total package, I would be dishonest.
When I think of the money they blew on this movie and what could have been achieved,it makes me want to hurt people, heck I feel dirty having paid to see it. I want it to bomb because I cared, and I now feel nothing of value will be lost. It's kind of like some shit-tastic game selling 20 million copies, though a bit different.