No doubt some men here (and some spouses of women here) fit this description, but not all. I believe that there are genuinely decent men who get into relationships with selfish women, and they are unhappy because of the resulting imbalances that exist because of that selfishness
I agree with you, Stu. The book was written by a self-described Nice Guy. The emphasis wasn't to point blame or rip on decent men. The goal was to show Nice Guy's how they were contributing to that imbalance you reference above.
If you are contributing to situation, you can impact that situation.
In a relationship, *our* choices can contribute to an increase of selfishness and ongoing selfishness in our spouse. Do you think that's possible?
Nice Guys often keep "sacrificing" in a relationship because they think "it's the right thing to do". With the unspoken belief that doing so will facilitate their spouse choosing to "do the right thing".
The NG is operating under the premise that his spouse has the same rules of relationship. She may not. She may be in the camp of "If you really want something, you'll fight, cuss and scream to get it" rule of engagement. That's the rule she goes by. So that's the one she implements when she has wants something. NG bites his tongue, sacrifices or sublimates and thinks, "I'll go along with her on this and next time she'll see what a good guy I was and will _____ for me." But that's not going to even register on her radar. Meek requests, pouting, whining, sighing deeply from the other room - will probably just irritate her. It will certainly not produce a sudden desire in her to do what you want. She isn't operating from your standard of "the right thing to do".
You can see how this can go horribly wrong.
The author does address the negative side of Nice Guy behaviors. And there are negative aspects.