Did you mostly hang out in bar/tourist areas? I ask because Isaan people are the majority of workers there. They are an ethnic group from the NorthEast. Darker skin, flatter noses - a different look from the paler Thai Chinese.
It's a different race of people that most are exposed to, compared to those working in Bangkok with wealthier Thai Chinese.
Not much, spent some time in Bangkok just on holiday. Went to Pataya for a weekend, not my thing.
But most of my time in Thailand was on a project site near Phuket.
Most of the people i met were country folk.
Good people, very ugly, but nice people.
Have nothing but nice things to say about their people in general.