I'm too new to sw to have a valid opinion on the benefits/negatives of sand. But I had Discus for years and the same bb vs. substrate argument raged although there were different aspects to it. One thing that was always said was that removing the sand would cause a catastrophe, and that's been said here too. I disproved that
here when I removed all sand/substrate from my planted tank. I had absolutely no problem after removing the substrate. But the reasons I removed it were the same as detailed here... too dirty looking, hard to keep clean, a potential nutrient sink. But that was my opinion of the esthetics, there were never any problems resulting from the substrate. I never experienced all of the supposed pitfalls that sand bottom owners have to fear. My nitrates were very low (cus of the daily w/c I'm sure) and there was no signs of anaerobic activity in the sand... no toxic bubbles coming up from it.
It was a continual battle with me between having sand & getting rid of it. In the end the reason I left the hobby was because of the incessant maintenance required for Discus. Daily w/c of 50% or more, bb being a necessity to maintain a starkly sterile tank etc. So when I flipped to s/w I didn't want to begin with the same attitude. So I've got about 2" of sand in a 65g tank. I don't siphon it, though I may start to if I see crap collecting on it. If it bothers me in the long run I'll just siphon it out like I did with my f/w tank. IMO a bare tank looks out of place and I hope I don't end up there. I've seen mature bb s/w tanks and I don't like them.
I've also owned a LFS and I know that if I told customers that had substrate that as a result of having substrate they should do a lot more mtce on their tanks to alleviate the risks, they might leave the hobby too. On the other hand, if you tell your sand bottomed customers to leave the sand alone and let the tank handle it itself they might be more satisfied. You can bend the reality to fit your own preferences. And statistics can be used to prove anything.