I wonder who was "the guy manning the booth." The mask wearing anarchist or the suit wearing business man. Depending on who you met, you will get different answers to your questions, as their personality is the exact opposite. zkSNACKs is a company with over 30+ people already and opinions on blacklisting varies to a great degree from "this should'd been done long time ago" to "we must start working on decentralized coordination protocols." My take is that I'd not like to discriminate between users at all, but it had to be done, and I can only hope it wasn't already too late. At least Bitcoin privacy can flourish.