While having a github presence can help recruiters find you, you aren't required to have such presence at all; the vast majority of people I interview don't (and the same goes for coworkers).

Measuring lines of code written is another fallacy that gets thrown around easily, but that any engineer worth their salt knows is a stupid metric (1MLOC of shit code is a pile of shit). One only needs to look at their most recent perf evaluation to realize that absolute code output doesn't actually factor in - it's high level impact perception that does, if anything.

Being single doesn't in any way correlate to more dedication; plenty of singles clock 9-5 and spend free time on non-coding activities (games, TV, exercise, etc), and plenty of family people work late by choice. It's not even an either-or proposition either: there are married people w/ no kids, single people that need to pick up their dogs at daycare, people that work so late so often that they become unproductive due to fatigue, etc.

The idea that someone will take your name and go dig up all your personal info and discriminate you and cackle maniacally is just flat out absurd. As someone who's been both an outsider and an insider to bay area tech, I honestly don't see evidence of discrimination, deliberate or otherwise. I feel like the occam's razor in this discussion is that armchair speculators seal themselves in an echo chamber of delusional conspiracy theory out of self pity or to feel smug. I also noticed that there are people who have had asshat bosses/coworkers at companies w/ dysfunctional cultures and think that experience translates to there being asshats everywhere.