All Dominican Salons are not equal in care and service just like any other hair salon. Sometimes ppl have the misconception, because it's a Dominican Salon, your hair will grew. I've been to plenty/seen plenty of Dominican salons that use the cheapest of products, wash improperly, those who do not want to deep condition you and when they do, put you under the dryer for all but about 5 minutes. Have been very aggressive when combing through hair for roller sets, overlap relaxers, use regular shampoo rather than neutralizer, etc etc etc. The list can go on and on. And sometimes, the major factor is the communication issue.
However, I have been to dominican salons, if the stylist notices an issue with your hair, she'll go in the back, concot up some formula, deep condition you properly, make suggestions, offer advice and etc.
PPL who go to dominican salons who experience the thinning and damage is usually because they are overlapping the relaxer, relaxing too straight and blowdrying each week.