I am talking about work being done in clinical trials at reputable medical clinics. They may be mistaken but I don't think it's "silliness." Here is a recent clinical trial evaluating UVBI https://www.tandfonline.com/doi/full/10.1080/2331205X.2019.1...
Of course there are many other mainstream treatments that came from somewhat oddball ideas: Sister Kenney's treatments for polio, the Nobel prize winning discovery by Barry Marshall and Robin Warren that ulcers were caused by bacteria (H. Pylori), the use of leaches for treatment of venous congestion after surgery, and the use of maggots for wound debridement.
I suspect this may be a case of "the dose makes the poison."
You may be generalizing from a specific experience or specific experiment and rejecting a modality that may have significant efficacy.
It's hard to tell what you are basing your assertions on because you offer no specifics. My "watch list" interest is based on the number of positive experimental results and ongoing investigations of the technique.
Of course there are many other mainstream treatments that came from somewhat oddball ideas: Sister Kenney's treatments for polio, the Nobel prize winning discovery by Barry Marshall and Robin Warren that ulcers were caused by bacteria (H. Pylori), the use of leaches for treatment of venous congestion after surgery, and the use of maggots for wound debridement.