three points I picked up on:
BB is not the new fad, tanks/aquariums were run BB for decades before sand became popular. Sand was considered lethal with the exception of trying to maintain benthic organisms.
I don't see a lot of people changing back. Most people that are BB you don't hear from. They have other things to do with their time. But just like anything else, you do hear from people that have problems with things, that's what we're here for.
Probably the biggest problem with people changing over to BB tanks is what has already been beat into their heads from running DBS systems. Most, if not all, of the hobby literature is geared towards running tanks with sand beds. More Ca, more lighting, more alk, more carbon, more more more sell sell sell.
People have a hard time forgetting everything they think they know, and starting over with something totally new. As result, you end up with this hybrid method of running a BB system where people tend to use too much light, keep alk and Ca levels way too high, are now scared of a little detritus and don't feed enough.
....no matter how many times or how many ways you might try to explain it to them. And the hobby literature is slanted to explain things in a way that makes that method "feel" right, natural, and all goose bumpy wholesome. It does not explain how things really work so people know what they are really doing and why.
