I know some people who liked it (though they qualified that), I mean it's all personal taste at the end of the day but personally I thought it was a complete unmitigated train wreck, just like Man of Steel.
I know this will sound patronising but I really think the movie's defenders just really REALLY wanted it to be good. I really want to see a good Superman/Batman/Wonder Woman/Justice League movie too, but I'm not willing to sift through a pile of crap for a few crumbs of goodness. Those characters deserve an actually good movie.
And it's not like it can't be done. Look at Marvel, they're scoring home runs with their B list heroes, and DC is still fucking up their A list.