It really has very little to do with men "being owed sex" by women. Most men don't really believe they're owed sex by women, or anyone for that matter. The big issue is that society has placed such an emphasis on premarital sex and random hookups and casual sex that young men are beginning to feel like if they aren't having sex they are missing out on an integral part of life, which is not the case.
Sure, there are definitely men out there who truly believe that women are simply there to please them and be their slaves, but that is not the case for the vast majority of men, even so-called incels. They have simply been led to believe that sex is an amazing, huge part of life, that it is integral to a normal life and, while it is important to a healthy relationship, it's not necessary to live a normal life.
It also comes back, in a way, to the destruction of traditional masculinity. If they can convince millions of men that sex is the only thing that matters, that it is the most important part of a relationship and of life, then that's all they're going to care about. They're not going to focus on other things such as learning new skills or trade or bettering themselves in some other way.
Of course, the funny part of all this is that by convincing men that sex is the only thing that matters, they are completely reducing women to only being important in a sexual way. Although, I suppose that's part of the plan too. After all, we can't have women being motherly figures or caring individuals in a household or in life in general. We have to have them choose careers that debase them and destroy their mental well-being. It really is all connected I guess. The destruction of the family unit, the destruction of traditional masculinity, the destruction of traditional femininity, the sexualization of children... It really does circle back to the destruction of traditional values in a way that lets them swoop in and replace traditional morality with some sort of perverted new age "progressive" morality.
Anyway, that's my $0.02
The sexual revolution only benefited men.
Women, typically the gatekeepers of sex, were convinced that they should go and give it out, otherwise the other girls will, causing them to compete by offering sex at higher rates. Women are now more sexual objects than before, and despite the higher amounts of sex, very promiscuous women are still stigmatized just like before the sexual revolution. It's almost like they gained nothing but sex.
Men, who have the higher sex drives, were only happy to oblige. The fact that the prediliction of some existing societal problems are based on this are oblivious to women and men. Example: Abortion is an issue between right of life or a right to choose - in reality, Abortion wouldn't be a problem if people were willing to admit that its rates are very high when value on sex is very low a la the sexual revolution. No sides (women or men) want to say to "have less extramarital sex" as a way to solve Abortion, so they keep supporting nonsolutions, like access to contraceptives or banning abortion.
But you can't let the genie out of the bottle - people are too sex-addicted to admit that sex is creating this problem and we really have to have less of it before marriage. As a married man, I can definitely say sex is very hard to turn down once you have permanent access to it - for the unmarried to get access to this benefit it is reasonable to see why they refuse to simply say that sex outside of marriage is the problem - it's very hard to turn down.