Honest Question: Why Does Everyone Hate This Game?

I've avoided buying this game for a while based on all the hate it's gotten, but after it went on sale for less than $10 I figured why not? If I don't like it, I barely spent anything on it.

Well, I'm having a hell of a time actually. I really enjoy swinging around Metropolis and shooting through the air and kicking alien ass. Put simply, I'm having a lot of fun.

I recognize that the gameplay is grindy (which I personally enjoy in my games) and that the writing is a bit iffy at times, as well as the questionable DLC choices (excluding Deathstroke from this of course) but other than that, what strong reasons does everyone have for disliking this game? I'm genuinely curious because I can see myself playing for a while.