Except unlike that case, there can be studies to measure impact of environment on people's success outcomes. And there have been. It's a valuable topic to discuss, with accurate date - not repeating the same bootstrap fallacies that simplify the world for people's comfort.
> We found that Asian-American women performed better on a mathematics test when their ethnic identity was activated, but worse when their gender identity was activated, compared with a control group who had neither identity activated
http://journals.sagepub.com/doi/abs/10.1111/1467-9280.00111
Could it be that given the right priming, people can improve their lives? What's the effect size of society vs individual? And even if it's 90% environment and 10% the person, it's often easier to change ourselves than our environment, so shouldn't we encourage people to work on themselves?
Of course care must be taken not to make it seem like a moral failing for not "trying hard enough", I think that's where people find the "pull yourself up" crowd distasteful. But there must be some way to give people the confidence to try to work on themselves without discouraging them by making it seem like it's their fault. Does that make sense?
I haven't found the right word for it, but it seems to be loosely related to a personality attribute:
https://en.wikipedia.org/wiki/Locus_of_control
Which if true, would mean nobody's changing their mind. It would be like an argument between a staunch introvert and extravert arguing over whether or not socializing is exhilarating or draining.