It's interesting that this article gets reposted a lot to confirm people's preconceived notions, even though if you actually read the article it is a lot more complex than that. I don't think you can really simplify it into "women say no, men say yes." For one thing, the main factor affecting people's answer is how safe they feel. If women felt safe, they were more likely to be DTF. Also:

Conley conjectures, “In sum, when women conceptualized the unknown proposer, they appeared to be thinking of someone like Carrot Top. When men conceptualized the unknown proposer, they appeared to be thinking of someone like Jennifer Lopez.” [p.320.]

In other words, all the guys posting here saying they'd totally bang a woman who wanted sex up front is being overly optimistic--they're imagining a woman who's actually in their range of attractiveness. They're not thinking of someone who looks like Roseanne or Susan Boyle, and if you take a look around at the people you see in daily life, there are a lot of women who look just like that, they're just not registering in your head when doing thought experiments like "what if a girl asked me to suck her pussy?" Women are more pessimistic, they assume sex with a stranger means they're having sex with an ugly man. The results showed that if men and women KNEW what the stranger looked like, the gap between saying yes or no lessened significantly. That is, men and women want to have sex with attractive strangers, and they don't want to have sex with unattractive strangers. Unsurprising.

So, what you find in many of these comments ("I would do any girl who asks" vs. "girls would call the cops on me and call me a freak") is not representative of overall human interactions, though maybe it's just a reflection on what will happen with redditors.