Looks good to me - she has a lovely small waist & a large ass. If she was fat, I'd understand the negative comments.
Just think of that ass like a pair of tits - some girls are bigger than others. This gal is just built with a big, round ass.
I've seen nothing to put me off so far and my girl only weighs 88lbs - that's about a half of what this girls ass weighs.
Presuming her face isn't too bad - I'd hit it.