Why do girls say they want a nice guy?

This charming phrase from the current president in regards on how to treat women: "You have to treat 'em like shit.".

Probably for the same sort of reason that I say I want ten million dollars.

you should ask halomaniac out.

Guys aren't much different, we fantasize about the cute 'girl next door' Mary Anne type that bangs like a $2k/night hooker.

If you just want to get laid, the best pick up line is, "Hi, I'm from out of town." Works even better if your friends introduce you around that way but if you aren't really from out of town it's not very repeatable. Also if a girl asks you to buy her a drink or borrow money, ask what you get out of it. If she says "nothing" or similar, tell her to buzz off. It gets under their skin because most guys will just buy them a drink without asking for anything in return. But really, don't give them money or buy them anything unless they tell you what you're getting in return. Good girls won't pull that stuff so no worries, you're not losing a potential spouse.

Women LIKE MASCULINITY, nobody likes asshole.

I feel you answered your own question. These girls who were physically attracted to you weren't looking for a relationship. When you showed them who you were, they were disinterested not in your personality as it stands, but because they were never interested in your personality. In other words, they didn't want to date you either before or after getting to know you. Hence the word "physically" attracted, not romantically attracted.

So there's your mistake right there. And it's one women make, too. Often. They're good to the people they're attracted to, but are pissed when the attraction isn't returned over time, even though it was never promised. And then they consider those people assholes and end up saying they just want someone nice, when the reality is those assholes were never assholes to begin with.

As for what women want...it differs in individuals, regardless of gender.

For me as a woman, I don't understand the whole dating scene now. I don't enjoy being hit on by strange guys I've never spoken to, I don't do casual hookups, and I don't try to build relationships from these. I fall for people that are friends first, that I get to know first, and that's how they become attractive to me. Maybe I'm just old-fashioned or something, beats me.

Men are exactly the same way...chasing the bad girls. They are even worse at chasing the physical and ignoring all the red flags
I think when people are young they can't discern between lust/attraction and love. It doesn't help that everyone puts their best side forward at the beginning.

I think it takes maturity and experience to appreciate qualities like "nice" and those that will treat you well.

And men say they want a nice girl, but all go after the high maintenance slut bag.