This is bizarre to me because when I hang out with friends and former coworkers we can't help but touch on programming and work in some way.
Is this situation common? Is this a red flag of sorts?
This kind of culture pretty much sucks and in my experience comes from the manager's conception of the software development process being akin to handing out individual long-running homework assignments. If someone is so out of touch that they literally do not know that deep collaboration in software development is even possible, then of course they will not promote it.
Anyone unhappy with the culture has a duty to put some effort into improving things, but if the total number of people who actually care is low...
I'd say, yeah, that's a red flag. You aren't discussing issues and making decisions with input even from your own team members?