You're basing this one nothing. Literally none of the comic book "experts" I know personally like the movie. Their highest review seems to be "Meh."
Im as big a comic book and comic book movie fan as anyone, and this movie was thoroughly disappointing even as I'd agree that it's not as bad as the aggregate scores can make it seem (stuff like 29% on RT).
People with personal connections to the characters seem to be having the biggest problem. Batman killing people, batman being an idiot, stupid reasons for them fighting each other, lack of or laughable motivations for the characters, a waste of Doomsday.
This is what comic book fans are saying, not film critics.
If you liked it, that's cool. But let's not throw out some sort of pretentious "Comic Book Expert" opinion as if you aren't a minority even among the die hard audience of this movie.