Airports are like movies and concerts in that they encourage asshole behavior hand “It’s all about me” thinking. I don’t know why, and not everyone does it, but it seems easier to get to that point when flying.
I typically check my bags. Either I’m meeting Tom and my flight is first anyway so I have time, or I’m traveling long enough that I need my big bag. 9 out of 10 times, even when I’m flying with my smaller luggage (that can fit overhead) I check it.
I understand a lot of people are in a hurry (whether they really are or just think they are) and don’t want to wait for luggage, that’s ok. But those same people seem to usually be the ones who can’t or won’t grasp the “must fit in overhead, and only 1 allowed” rule. I’ve seen people with 2 rolly bags, 1 rolly bag, and a huge duffel, etc. there’s many variations.