While many cultures are different, I think we can talk about average culture, especially given certain selections. Average culture of people who use a dating app is likely different than average culture of people who scorn dating apps, and we can talk about what happens in each. There will be exceptions, but this seems true of any psychological/sociological statements. When we are talking about cultural norms, we are talking about averages recognizing there are sub-cultures and counter-cultures which can be quite different.

Take doing interviews (since I think that will be less controversial of a median to talk in). There is general advice on what one should do for an interview. It may be that you will be interviewing with someone whose opinion of you will go up when the see you in a t-shirt and flip flops, but when asked advice on what to wear to an interview we still tend to give advice based on the averages of wearing somewhere between business casual to business formal. We even stereotype different types of business culture (mobile startup vs international bank), and rarely do people point out a lack of peer reviewed studies or that there will be exceptions (or if they point out exceptions, they do it in addition to, instead of as a counter of, the standard advice).

>Before it was paid very well, being a "computer science programming nerd" had a very low status in general society.

Being very stereotypical and based on anecdotal evidence, but it still seems pretty low status (in the overall culture) despite the money to be made.