Yep, I know exactly what you're talking about! Quora is particularly bad about this. Someone will ask a health-related question and get a response like, "Go see a doctor, you dummy!" Of course, advice from strangers on the internet isn't a substitute for actually seeing a doctor, but typically when people pose these questions, they have already exhausted their resources -- perhaps they've already seen multiple doctors and failed to receive a satisfactory answer (certainly wouldn't be the first time that happened) -- and are looking for someone to point them in the right direction, not to give them a diagnosis. They understand at the end of the day, it is up to them to use discernment when evaluating this information. Point is, if you don't have anything helpful to say, don't say anything at all!