Look at the supplements world, where grifters are shilling chemicals that cause harm and make radical claims for absurd markups. Or gas station pills. You want those companies making Alzheimer's tests? People going in to a 7-11 and buying a "all illness test card" that tells people they do or don't have degenerative diseases?
No, it's very very important to ensure tests are actually indicative and ensure they are well made. To do that, a regulating body needs to be involved.