Very interesting question.
This might be a bit rambling/out loud thinking!
I think part of it is a disconnect between a fast moving (in terms of social values) society in some respects, but a lot of individuals within that society who have still been brought up with "traditional" expectations.
Because it seems to me that no matter how liberal a (some!) guy professes himself to be, as soon as he gets in a long term relationship/married the traditional expectations come sliding back in.
Especially around expectations of sex.
When you match that up with the fact that more and more women are working as well (and I hate this career shit btw...not all working mums are in "careers"....more often than not in "menial", nmw, f/t work where childcare is barely covered by the wage) and yet still saddled (mainly by default) most of the household work, you get an "explosive" situation.
So....
Man resents wife (poss subconciously) for not giving him duty sex/working too much/not jumping on command/expecting him to pull his weight house-wise/earning more than him/progressing further in a career as these expectations are culturally engrained still, especially if your parents have strict trad roles.
Woman resents man because despite being promised equality, and poss/prob working fulltime it's still ends up being down to her to organise childcare/sort house out/"nag" husband/be attractive/be sexy/have sex on demand/do a million little jobs/plan things/empty the dishwasher/ all those things there are a million threads on MN about.
Plus I do think there is an aspect of men becoming ever more resentful of women.