Sorry, but you are completely misunderstanding what “descriptivism” means, why it’s the viewpoint taken in serious linguistics, and how common it is there (i.e. absolutely 100% universal among everyone who studies language scientifically).
The point of science is to understand natural phenomena, not to pass value judgments on them. Biologists’ job is not to decide which out of dogs and cats is “correct”. Why should linguistics be any different?
