Many ways to skin a cat...
I'm personally enjoying the bonsai inspired reefs on the other big forum. Not a whole lot of live rock... it makes the tank look bigger than what it is. It used to be that you had to slam your tank full of live rock to get enough benthic creatures and anaerobic zones to keep your tank cycling to the max - but these days with the development of DSB refugiums for benthic and anaerobic zones as well as powerful protein skimmers for excess particulate and dissolved organic matter removal - the amount of live rock needed these days is becoming more and more debated.
Some tanks these days are completely started with base rock only... and are kept as successful SPS dominated reef tanks. How would you explain that?
In my PERSONAL reefkeeping theory and opinion, A tank can have as much or as little live rock as the aquarist PREFERS in his display tank. If the tank looks good with more rock to the aquarist - go for it. If the tank should be set up bonsai - go for it. With the development of technology and equipment such as skimmers,macroalgae and benthic zone refugiums, remote deep sand beds, and even artificial mechanical and biological filtration systems - the amount of live rock needed now is ... moot. Kind of like how LED's make the "watt per gallon" rule extinct.