I don't see any ethical problem with people doing experiments on themselves. That said, they should know what they're getting themselves in for, so I applaud these researchers for highlighting the dangers.

> One could say "they shouldn't be doing that", but don't researchers want their results to be used for something, or is it just about publication?

I imagine they would like their results to be used for positive purposes. If people are misapplying the methods and permanently damaging themselves, I doubt the scientists are super happy about that just because their research got applied somewhere.