So they think the UK's main centre-left party has an "unwritten rule" against female leaders, when its main centre-right party very obviously doesn't (having a female leader right now, its fourth, and having just last month marked the fiftieth anniversary of its first election of a female leader). How do they explain that? I mean, what about the UK Labour Party's ideology leads it to having an "unwritten rule" against female leadership at its highest level, while the ideology of the UK Conservative Party leads them to embrace such leadership repeatedly?
It's a party about working men not actually a "centre-left party". Hence its decision to humiliate and probably in some cases kill people in order to "encourage work". It looks centre-left on a simplistic axis where the Protestant Work Ethic is assumed as some sort of necessary background rather than an increasingly weird religious belief.
The US does have this problem to a greater extent - don't get me wrong - but the UK doesn't really have a party which is open to the idea that maybe the objectionable thing isn't the use of the words Arbeit Macht Frei over those German camps, the problem is that they're not true.