I once watched a fistfight almost break out in the office over threads vs. event loops. Both engineers were in their mid 20's (as I was, at the time).
From my limited experience, pig headedness seems to be a personality trait - not something intrinsically age related.
I get that it might be amusing for you when people complain about an overtime that's three hours less than your total workday, but it really is quite unnatural for someone to work for that long. Spending 70% of your waking hours at work is not something to be proud of.
The rest is quite good to hear as an anecdote, however. It's great to hear about teams that socialize in a way that doesn't involve beer, pingpong, or partying. Strange sort of frat culture that we live in.
Why are you working 11-hour days when your colleagues are working 8-hour days?
Sometime people go out to a bar or something afterwards. I may feel like I'm missing out but it never feels like something I "should" be doing.
It's entirely possible to do your research and evaluate a framework, language, or tool without having to use it, just like I don't have to go out and shoot some smack to know that heroin is probably not for me. Being able to evaluate what your needs and wants for a tool are, without having to write a To Do list is a useful skill.
Research may be enough. But research + trying a simple prototype is always better.
The solution to the happy-hour problem is to have your happy hours during work, not after hours. Even I, who am young, healthy, no kids and loves beer, would get tired of having to go to xyz happy hour at 6p.m just to keep my edge.
The other thing: I bet that old guy is the first one in every morning. And probably brings his lunch every day. Also is not interested in an afternoon ping pong break. Translation: He or she probably actually works more, despite being "at work" less.