It's funny, we all have different levels of paranoia or concern about materials and methods. Because we ingest the vapor and gasses into our lungs, safety does matter, and the amount of risk we are willing to take is going to be different for everyone. I think it is important that folks know the risks they are taking so they can make educated decisions. While that may be less important for us old farts on the last quarter of our lives, it should be of greater importance for those on their first or second quarter, as their own chemical machine will need to last much longer.
For example, I love butane vapes, but I hate butane. So the butane vapes I am willing to use are like the Lotus and the Vapcap where the butane flame is not part of the air path. One heats a metal plate (Lotus) or a metal cap (VC) and that radiates heat and heats the air as it is pulled past the radiator and then through the load. There is no way to inhale the exhaust of the butane flame, you just use the radiated heat.
That is different from something like the StickyBrick/Daisy or the Flam where you point the torch directly in to the air path and inhale the exhaust with the heat. That may be perfectly safe, I can't say for sure, but it certainly causes my paranoia flags to light up. And while I wouldn't be afraid to take a hit from one of these devices if it was passed my way, I don't think I would be comfortable using one on a daily basis.
We all have to make our own decisions. Lots of people are afraid of Lithium batteries, particularly the 18650s, so they wouldn't dream of using a 510 mod. Some won't use butane. Some would still rather combust. It's all mostly a matter of preference whether for safety or effectiveness, but in all cases we are better off knowing the risks.