I'm one of those people who feels really strongly about this, I am totally against the look of barebottom (and to each his own, I'm not saying don't do it or anything crazy), when I see it on those reefs which are just amazing, my rating for it goes from a 10 to a 6. It doesn't look natural at all, and to me it seems a bit to choosy, you can't try to recreate nature and leave out such a huge part.
There were plenty of reefs that I have snorkeled where sand was too deep to be seen, are those areas unnatural? Who's to say I'm not trying to re-create that scene?
If your idea behind a reef tank is to ONLY recreate nature, then I assume you are only keeping animals from certain areas. Fish, coral, inverts that are only found in the pacific would never reside along with those only found say in the Florida/Caribbean, otherwise it wouldn't look natural
I get your point as I used to be just like you because when I thought of a "traditional reef tank" it had a certain look and that look had sand or some other substrate. So to say it doesn't look natural isnt true, to say it doesn't look like a "traditional reef tank"...then you might be onto something. I absolutely hate tanks that look like they have a wall of rocks but hey, to each their own.
There's no right or wrong way to run a reef.