It is really simple actually, when one is nice but is expecting something in return, can we still consider that as someone genuinely nice? NO
There are shy girls with low-self esteem being nice to their crushes because they like them, but after their crushes get sexy, bitchy girlfriends, do they cry how they've been so nice and all but still not getting picked? Well, maybe yes. but not as much as most guys do.
I don't think society SHOULD have a structured system showing men how to be all manly and stuff, well ideally, that should be the case, but it would also mean that society should have the same thing for girls. Which I think is very unreachable. What it should be about is our own conscious choice to do what we think is right because it is what we believe is right rather than doing something cos it is what society dictates us to do, even if we don't get perks for doing it. Then there would be no stereotypes of ''nice guys'', ''bad guys'' and such. Everyone has his/her own good and bad side and learning how to be confident with oneself so if someone rejects him for being too nice, it wouldn't matter as much cos then he would know he only did what he think was right.
And lol at girls liking the ''bad guy'' image. That's just an image most girls get instantly attracted to but doesn't mean that they want to end up with that ''bad guy''. Just as most guys drool about women who shows more of her cleavage than her personality. At the end of the day, regardless of which stereotype or category you belong to, may it be ''bad guy'' or ''nice guy'', your partner will stick with you because of your being dependable, trust worthy, responsible, loving towards her and also that she loves you too and all in all that's what what the word ''nice'' really mean.
BTW, I've only read the first paragraph so if my post is so out of topic, I ask sorry in advance. I am just annoyed that people bash the idea of a nice guy and preach being a bad guy cos that's what girls like. Most people just don't understand what ''nice'' and ''bad'' really mean. Nice is when you have respect for everyone and etc, bad is when you treat every girl like a sex machine. arrogance =/= confidence=/= assholeness.
There's a time for dirtiness and naughtiness and there's also a time for niceness and decency.