You have the honor of being the first to make such a remark that I've heard/read. I'm personally not going to see it because I know I wouldn't like it. But that's the point, I don't go to movies just to see the new flick.
I was doubtful of the quality to begin with, so I admit I went in not expecting much, but so many people were looking forward to it that I thought I was missing something, that the movie would surprise me. For reference, I like comic book movies. I like even the bad ones. I enjoy Michael Bay movies on occasion, fully aware of how bad they are. Maybe this was just an adaptation of something I care about. I thought 300 was better than this, but because 300 is a far stupider book to adapt, it really is just a showcase of Frank Miller's cool art. I enjoyed almost every part of 300 except for the bits Snyder deemed to add to the plot, which were absolutely unnecessary.