a) Intelligence is strongly valued in general, with women being no exception. There is no native faux-ironic 'im a math geek nurrrg so i have to be awkward because noone understands me' or 'look at the nerd what a dork' culture..
b) Russian women aren't afraid of being strong willed, and this is also valued
c) Russian women seem to have a stronger notion of 'womanhood' and 'sisterhood' - similarly 'adulthood' and 'solidarity' are more generally valued - so hiding behind or supporting immaturity and selfishly infighting is less dominant/accepted
d) The general cultural philosophy is (despite bad eggs as anywhere) a focus on personal excellence and service to community/society/nation, rather than a desire for personal gratification according to abstract self-selected individual preferences
e) People call out BS when they see it, and this is considered a good thing, rather than 'being rude' or 'disrespecting everyones right to their own opinion'
So while perhaps sexist jokes and activities are allowed in some areas, in other areas actually acting on them - or letting them get to you or not calling them out in others - is dishonourable, a personal 'cultural liability' (e.g. cause for being ostracised), and to be avoided.
Of course there are exceptions everywhere, and this is observation and generalization - not an absolute statement of fact, also put with a bit of an ideal spin to underscore the argument..
Not sure if is 100% correct, but an interesting point of view nonetheless. Perhaps in Russia it is a similar effect, reversed.
To me it is the behavior of non-Russian societies behavior towards women that is ironic, acting as if there was this huge conspiracy from society to "keep women down", which I've always felt was utter nonsense but you dare not say such things in polite company, whereas according to this article, it is actually these do-gooders who think they are trying to help women who are actually the ones harming them!
That must be what you were thinking as well and I just misinterpreted you?
In western society an especially smart, capable woman has the option to gain status/prestige by studying feminism. Perhaps in Russia they don't have that option - there's no high-profile X-studies program to aspire to - so they learn something like math and excel at that instead.