fellow german and medical student here. the reason is twofold. The first part is pretty obvious, it’s a great way to make money for pharmacists and physicians, it’s pretty much unregulated, has huge margins and is often paid by the patient instead of the gesetzliche Krankenkassen.

The second part, why they are getting away with it, is that naturalistic and pseudoscientific healing BS has a long, long history in Germany. Schulmedizin, at least somewhat, had the image of being perverted by Jewish influences. "Völkische Medizin" the OG Heilpraktiker in some sense, started most of the Quack stuff you see today. The same circles are also still infested with nationalist and anti-jewish sentiments á la "the globalists" to this very day. It’s a crazy, crazy world if you take a closer look.