Looks like you missed this prominently placed note: "Online diagnosis is for informational and educational purposes only and should not be treated as a doctor's advice or medical consultation."
Having said that, this is not a commercial website. This is an open source[1] demo showing how can an online checkup tool work.
I don't think such kind of informational tools is a bad thing, even if they are commercial. In fact, these tools are helpful for personal research. Of course, actual diagnosis and treatment should be left to medical professionals. AI application in the medical domain is still in nascent stage and can presently only work as "assistive" at best. It is not going to become "prescriptive" or replace professionals in near future.