I think that it’s possible they realize privacy concerns are not foremost in the minds of people looking to hook up with perfect strangers. I would guess that “random hookup” and “serious about security” will tend to be mutually exclusive.
For example, even though drug deals are illegal and sketchy, there is still etiquette to be followed; there is still a chance you could be "sketchy" to the majority of drug dealers.
There is a proper way to behave for random hookups, and there is an improper way to behave. The difference may actually accentuated in hookups (and other high-risk activities) because there is more at stake.