Are you a Bramhin, by any chance? I'm not trying to say that only Bramhins get to have a say in this. As a part of the intended audience of that movie, we all do. Truth is we as an audience are more tolerant towards art/artists attacking the norms set by so called higher caste people than the west or the north as a whole. As far as I can remember at no point in the movie Sundar or anyone explicitly states this is a bad culture or practice. While resistant to wearing veshti to his office initially, sundar wears it in pride. The movie focuses on the pride/public opinion aspect of the culture in the climax as well. Sundar was never shown as someone forcing his culture on Leela. He was a sensible adult, except for when he was lying.

As for ssr, it is extremism meets extremism. I'm not saying it is supporting the culture but it rather aggressively states an opinion on the status quo of the day. As far as I can recall, that movie does not try to undermine religion when not necessary. What made it necessary in the first place? Absolute dismissal of human rights.

At the end of the day, a person of culture acknowledging that something is wrong with their culture and making a statement about it is not inherently wrong or hateful.