Disposition toward self-pity and the comfort it offers contributes to this, but I think the larger part is because of the equality and sameness narrative in the culture concurrent with an absence of education for becoming a well developed man.
Men are taught that men and women are equal, even the same, and then get angry when they get out into the sexual marketplace and find out that's not the case. On top of that, they aren't taught what they need in order to be viable as a man in the sexual marketplace, an education that should be general for the public. Pointers on how to flirt and especially how not to flirt, dealing with rejection, socially lubricative activities like dancing, the importance of having hobbies they enjoy that can also have women in them instead of both wasting their life on stuff like online dating and antisocial media and then complaining on top of that, having a good posture, making sure they have good hygiene and grooming, teaching them how the stuff in the gym works.
Males need to develop into men, but they aren't nurtured into do so. That hits both genders since women and desirable men. If men are turned into losers, women will feel they've lost too.