How common are these guys?

[Runner Runner]

I have seen this increasingly at the local casino, it's almost always an older guy doing it:

They back into some kind of a straight or a flush when they are in the blinds or they made a loose call with bad cards preflop and decide they want to just check it down because they either feel guilty or want to be nice. Then, someone bets into them to either try and steal the pot or maybe for value. So they get pissed off that the person wasn't accepting their gift, so they raise them and get paid off.

I have seen this a few times lately, is this just a fluke thing or is it common among older players.