That's a skewed conclusion you're drawing. Are you really surprised that people aren't willing to risk escalating the situation on a plane, arguing with what's likely the very inconsiderate person in front of them? Most people have an aversion to conflict. It doesn't mean "they're fine with it". You probably don’t advertise in real life how much you lean back and not care who’s behind you out of fear that people will change your opinion of you. Real life is a harsh mistress.

I've bumped into people and they said "sorry", do you think they wanted me to bump into them, liked it, and actually believed it was their mistake? No, I just tower at close to 2m so they didn't want to escalate the situation.

P.S. I always look at who sits behind me, if they're "space constrained" or not, and almost always ask if I can recline. Sometimes I don't bother, clearly the person will suffer. Sometimes they said "I'd rather not, thank you". Many times they said "fine". I used to fly a lot and my experience was very clearly not that "everyone is fine". I was never fine even if I didn't start arguing. So how would you have known?

Nor I. TFA is about a chess bot, yet here we are discussing seat reclining etiquette.

But also because with any shared resource there's an expectation of decency involved. Some people just betray that expectation. They're the ones with the mentality that "they shouldn't have served alcohol if they didn't want me to get insufferably drunk", "they shouldn't have put the candy out if they didn't want me to take all of it", "why is the swing there in the park if not for my kids to use them continuously to the disappointment of other kids".

When your wife was pregnant someone probably let her go ahead in a queue, have her some priority for something, etc. That was a person with common sense and decency, not asking "why do queues exist", who doesn't do something only if there's a law about it.

A question you can always ask yourself is "should I do it just because I can do it?". It will stop you from being needlessly inconsiderate many times, and maybe even make you a better person.