That's terrible advice. I don't know if any doctor that is "out to get you" by not ordering tests. Tests are not harmless. Improper testing can kill you. For example, you have a headache with no red flag symptoms. You keep pushing, some doctor orders an MRI and now you have what we call an incidentaloma. Some incidental mass that isn't going to cause you any issue and is unrelated to your headache. Now you latch on to this abnormal thing, you worry about it, it affects your life. More scans and tests are done to figure out what this is. Eventually a biopsy is offered. Good news, it's just some normal cells that happen to look funny on MRI, but completely benign. Bad news, the biopsy had complications and now you're wheelchair bound for the rest of your life.
It's thoughts like this where the "advocate for yourself" has turned into the "threaten the person that dedicated multiple decades of their life to help others to get what you want" that has lead to the insanely piss poor defensive medicine in the United States.
Tldr: refer every patient and order every tests until someone dies of bankruptcy or an unecessary complication because webmd.
Because tests have harm. The average persone doesn't understand what the sensitivity and specificity of a test means.