> The fact that members of oppressed groups can be bigoted (including against their own group) isn't a novel concept.
If women are being sexist against men, then men are also an oppressed group. This isn't a novel concept.
You're classifying one side as oppressed and the other as oppressor on the basis of a single data point - looking at the very top of society. This would be valid if gender roles were handed down from the top of society, but that's simply not the world you and I live in.
Modern gender roles are a much more grass-roots affair and women are perfectly positioned to influence them. Every complaint about gendered toys, for example, implicates women more so than men.
When mothers push gender roles on their sons that fathers do not, it is absurd to suggest that there is some self-sustaining system called "patriarchy" (literally "the rule of fathers") at fault. You may deny it, but it is a transparent attempt at denying women's agency and placing the blame on men instead.
Frankly, it's boring and at this point I'm comfortable discarding the opinions of anyone who uses the word "patriarchy" outside discussions on religion (i.e. the only context in which gender roles are still top-down).
> Rich people and families with old money are over-represented in government. And yet we must presume that poor people voted to get them in place too
While wealthier people have advantages in terms of getting into politics, they still have to conform to popular opinion to get elected. Most European countries have strong labour movements that reflect this. I don't deny that men have an advantage getting into politics. I do deny that this single data point is sufficient to prove an oppressor/oppressed relationship between men/women. Gender roles are a trade, and women are active participants.