They're idiots. Certificates mean very little - just see how often the LA porn industry shuts down after performers get infected. Health is wealth, the financial rewards are just not worth the risks.
As for punting bareback, not for all the tea in China. If anyone thinks it a worthwhile activity, there's a site out there for men looking to infect/get infected. If that don't bring BB guys to their senses, they need a check up from the neck up IMO.