Provocative idea: maybe modern Russia is just bad at getting men into tech, so that a relative large part of the existing STEM inertia left over from Soviet days falls on women? Not saying that it is true, but from my outside perspective, it could be part of the puzzle.

Also, the Soviet era contained a lot of progressives in terms of gender roles. That is easy to forget with today's stereotypes of male-exclusive buddy networks on all levels of economic success and high-heeled golddiggers. (again: outside perspective! I don't know the facts on the ground, just talking about perception)