The myth of the ‛nice guy syndrome’ stems from a few assumptions. First I'll mention some very dishonest ones that are just there to stifle the discussion, then some more complicated ones but imho just as untrue.

The first dishonest one is that there is nothing special about being nice, that nice is the way everyone should behave towards everyone, that you don’t deserve praise for it, let alone any reward. Wrong! Decent is the way you should behave towards everyone. Being nice is a choice to put some energy in somebody or a group of people, to sacrifice some of your time or other resources, to be genuinely interested, to support others if necessary. The idea that is the minimum you demand of everybody is nonsense. (Especially coming from feminists who certainly are not automatically nice to men, but again: even they do not have to.)

Then an even more dishonest assumption stems from changing the definition of ‛nice’ and stating nice guys are nice because they have no other interesting qualities or characteristics. The definition of nice guys is that they are nice, not that they are nothing else that is worthy. Besides, you wonder what exactly is meant by those other qualifications a nice man should have to make him really nice and not just creepy.

More complicated is the idea that nice guys just want to get laid (a horrible way of talking about desire for sex and intimacy anyway) and only are nice hoping to buy sex that way. That may happen sometimes, and in a really insincere way; but when that is not the case it is still hard to falsify when a man behaves nicely and hopes to have sex, not an unusual or deplorable combination. You can even wonder if not any man trying to get sex does something for it, or if being nice is the worst way to do it, and makes it less sincere than f ex showing off his wealth by buying drinks, or his physical strength by... you name it.

Then, personally I think (and that is the best argument against the ‛syndrome’ thing) a nice guy mostly is nice because that is his nature. If he were just that way to ‛get laid’ he could change his attitude soon enough as he found out it didn’t work. The problem is, he can’t. He likes to please people, be patient, listen to others, etc. (Which by the way doesn’t necessarily mean he lets himself be taken advantage of.)

But he can feel disappointed when he finds out his attitude is not or hardly validated as a quality for love or partnership. That is not the same as feeling ‛entitled’ or demanding sex from women in exchange for niceness - that again is part of the ‛nice guy syndrome’ myth.

Maybe Karen Straughan is right when she states this whole myth is based on feminist feelings of guilt. If women really wanted men to be non-agressive and supportive and tender, they just could select them, no doubt women have that power. But as a tough, dominant man was more useful in primeval times, their genes still think them more attractive. To avoid this conversation they start blaming ‛nice guys’ instead of their preferences.

To make it more complicated, MGTOW’s, PUA’s, ShoeOnHead, Jordan Peterson also tend to ridicule or denounce nice guys, and even some MRA’s who confuse nice guys with feminist men. This makes the whole conversation about it only harder.

Most important: the disappointment of nice guys may not just be caused by the lack of intimacy, but even more by the notion that, even if you do get sex, your nice behavior will have played such a small part in managing it, which makes it not what you hoped it would be; because in your dreams intimacy would have been the result (not the reward, the difference is crucial) of somebody thinking you have a lovely character.