I reckon most of these guys are below the age of 50, they are looking for a convenient, affordable way to live and stay in Thailand. This is also the case for those over 50yo, they can live here cheaply, if married.
I started living here in my 30's, I've been working offshore, on a monthly rotation, before I turned 50 I would just fly in on a 30 day visa, the bar girl husband's can't do this.