I am a little confused about your first paragraph. I agree that it is patronizing to decide what some else should choose for a career and I hope that I didn't give that impression. Similarly, societal pressure does come largely from individual actions, but I don't think that it is wrong to identify problematic individual actions. Of course we should help those who are bigoted to understand the hurt that they are causing. It's an application of the golden rule (one statement of which is "don't do unto others as you would not have done unto yourself"), and so individual choices which cause harm to others should be overruled.
Note - obviously this is a simplification and it is often difficult to determine what choices will hurt whom and to whose benefit. The world isn't black and white and I acknowledge that.
I have never been harassed about being a man for my interest in computer science, biology, chemistry, physics or engineering (in which I ultimately majored). This is a good thing. Many women who have had an interest in those fields have experienced harassment or discrimination because of their gender. Some have also been fortunate enough to have been spared. Some men have probably been harassed for being one of the many men in STEM/ET as if their interest is their fault. Harassing anyone for wanting to explore their passions is unequivocally wrong.
And societal pressure comes largely from individual actions. If its wrong to overrule individual choices, then we're left with influencing folks early, perhaps with better role models.
I happen to know male nurses and female programmers. Sometimes I find myself thinking it a little odd, and take pains to show no surprise and make no remark that would reinforce my internal stereotypes.