I know you don't mean to be condescending, but so many punters like you on AN who assume they are always talking at a Newb if they've been here for a minute.
I've been to nearly every part of Bangkok imaginable. I don't live in a Soi Nowhere, thankfully, but I've seen many of them. They all get foreigners from time to time too. And I am happy to live where there is a greater concentration of expats, not because I want to be surrounded by them, but because it makes the services I want more readily available. Everything I need is within walking distance as a result. So it's an issue of convenience.
Unfortunately most of us have been to Chaengwattana, many more times than we'd like to in fact. Thousands of foreigners going out there everyday for a bit more ink in their passports.
First time I was in Phuket, Bangla Road was just dirt and not paved. The potholes could be daunting driving along on the GSXR I had rented. But the smiles of the girls back then made up for it.
I also used to teach a course at a Thai university and in Thai 😉