I think what he's describing is more common than you'd prefer to admit. It's not universal, but it's not uncommon either, so it's probably more accurate to say that he knows two men in the unluckiest quartile. That said, one can't always place the blame on the women deliberately changing into bad people after marriage; a more likely explanation is that the men ignored warning signs early in the process, because they were in love. The phenomenon of a relationship fizzling out and turning hellish is not unique to the US.
No one with a brain will say that all American women are bad. This country is way too racially and culturally diverse for a statement like that to be valid across the board. It's just much harder to find decent women if your selection pool overlaps significantly with the suburban American mainstream, because that section of society is a materialistic, vapid, and alienating cultural wasteland. Decent women exist everywhere, but the proportions are lower.
I believe your somewhat right with your first point. The friends he knows are two unlucky, weak personality males who were too blind or too stupid to realise the inherent problems in getting into a relationship with a dominant woman.
I'm married and extremely happy. My wife has a dominant personality and I have a comparatively relaxed personality, I take things much easier yet I learnt from an early age (with help from my father) that you have to establish your boundaries. When my wife is being snappy or pushy I simply say "do not talk to me like that, I do not appreciate it" and I rarely have a problem beyond that.
I know how I should be treated, I know exactly how much respect I should be getting from my spouse and despite being an easy going person I know I have to stand up for myself because if I don't I'll end up a pathetic divorced loser like so many people do.
Edit: I'd also like to add that most of my friends are in stable happy relationships. In fact I'd probably say my friends in relationships are happier than those who aren't, and I simply don't buy the whole 'getting married makes you unhappy' BS people purport.
No one with a brain will say that all American women are bad. This country is way too racially and culturally diverse for a statement like that to be valid across the board. It's just much harder to find decent women if your selection pool overlaps significantly with the suburban American mainstream, because that section of society is a materialistic, vapid, and alienating cultural wasteland. Decent women exist everywhere, but the proportions are lower.