I get Dominican blow outs, but I only get my roots done, and my hair is VERY THICK, and my scalp can take just about anything. When I go, I always get a DC and leave in and only allow my roots to be blown out, even if the stylist argues with me because she doesn;t think my hair will turn our nicely (and then by the time she's done, other stylists are always around her chair trying to figure out how she got my hair to look like that, but I digress
). My mother's hair is VERY FINE, and she has a sensitive scalp, and allowed them to do all those steps just about each time - roller set, blow out, flat iron.
I warned her against going, but she wanted her hair to look like mine and thought that was the only option, and I especially warned her against getting a relaxer once she wanted to go twice a month. She didn't listen to me and just rolled her eyes.
This time last year, her hair was longer than mine is now. She had to stop going to the Dominican salon because her edges and nape broke off around the entire perimeter of her head, and she got a bald spot in the middle. She had to get a bob cut last week to try to get back some thickness and body to her hair, because there's only so much styling and curling can do when you don't have any natural weight left to your hair.
So, whether Dominican salons will leave you with the hair on your head and whether it is fine to go is very individualistic, but I don't think ladies here are completely criminalizing Dominican salons.
There are few heads that can take all that.