The stripper being killed just seems like a lazy plot point. They needed to kill someone in the house for the rest of the film to work, so it could have been a pizza delivery guy or a stripper or a plumber or just some random guy they met at a club and really, I don't think any of those choices are more morally questionable than any other.
There were people in the backlash who were asking how people would react if it had been a chef they'd privately ordered to cater, would people still see it as dark humour, or would they see it more so as kind of fucked up?
There's a ton of precedent for this type of film too - Very Bad Things, Weekend at Bernie's, Don't Tell Mom the Babysitter's Dead, etc If anything, the backlash feels a little sexist to me. Men have been making dark comedies with amoral characters based around similar subject matter for decades and rarely faced any backlash for it. I don't see what the issue is now that women are making those same movies.