I can't compare to the conferences but I've read the same about not being able to buy with BTC. It just needs to be the unit of account for at least bitcoiners (imho).
On the other point, you're absolutely right, too.
I often forget that there are still people out there who do not think that Bitcoin is a good idea..
However, idk in these places like bitcoonbeach, bitcoinjungle or bitcoinisland and so on, it SHOULD be possible.
I mean in my childhood I bought "local market coupons" which I could only use on this one market for food or rides.. It should be possible to do the same again, but with Bitcoin lightning. One would only need a critical mass of merchants and musicians and so on (security and background organization doesnt need to be). That would mean around 30 - 40 bitcoiners should be easily enough to create an experience people (nocoiners) would like to participate in, I guess. They would buy sats on the entrance and getting orangepilled on the exit.
I mean, I am good at cutting speeches to other peoples beats (at least I think so), can cook various tasty and healthy stuff and am good at story telling...
So with you, we are two!