The idea of Stalin being soley responsible for it (or anything else in the ussr) is absurd. That said, it is true that under Stalin in the mid 30s the Communist Party stopped, dropped and rolled back many of the progressive social/cultural changes they introduced in the 20s (after like 1924, also under Stalin!). This included gender roles, arts, nationalities policy, labour, etc.

The influence of the rank and file party members through property party procedures and through refusing to carry out policy cannot be ignored. In the late 20s, for example the whole CEC is onboard with indigenization of the national republics, but party members (especially Great Russians) often disapproved and refused to carry out orders. A large part of this is a large minority, bordering on majority of the rank and file party members, were russians who disapproved of affirmative action and having to learn and use non-russian languages

For a variety of reasons, those refusing to carry out economic orders were punished much, much more harshly than refusing to carry out social/cultural orders, so e.g. suspected "national right communists" were punished much more harshly than confirmed "Great Russian Chauvinists." In all instances, the priority (particularly from 1929 on) was increasing production, with all other goals often ignored if and when inhibiting increased production.

The result is that some.Russian saying e.g. "Kazakh concerns over new agricultural methods are just local superstitions" gets a reprimand; while "our people dont agree with this new factory on our land" gets a prison sentance. I havent studied it in detail, but i have seen mentioned (in Martin, Affirmative Action Empire) that similar processes were at work wrt gender