...or, at least part of the reason that it didn't catch on with general audiences. They gave 'em the old bait and switch. They tried to sell it as like a grown-up version of Mean Girls or some shit. People thought they were going to see a straight forward comedy about some dumb, bitchy lady who stuck on her old glory days. They didn't know it was going to be a dark, nuanced character study. I remember stumbling across some funny user reviews of this movie on iTunes where people were like "OMG Worst Movie Ever! It was NOT funny AT ALL. Total waste of time."

The reluctance of audiences to embrace female antiheroes probably didn't help either though, I agree.

(It's also probably worth noting that this was actually fairly well-received critically, with a pretty solid score of 73 on metacritic.)