The problem with not using ANY live rock is you lose all the diversity that you could have. Using bacteria-containing products like Stability/Microbacter7/Polyp Labs/etc all add beneficial bacteria to accomplish various tasks, but they all certainly lack the diversity of plain ole' live rock. Sure, you risk adding some aiptasia or majanoes, but I've never been overrun by either of those. I may have lots of aiptasia that I cannot see, but if I can't see it, I don't care. Same with the pest worms, if I can't see their damage, I don't care.
Besides, if anyone is keeping corals, I'd be more concerned about red bugs, AEFW, pest nudibranches, etc. All the dead rock in the world won't help you out there. Pest hitchhikers can come just as easily from your corals as from live rock.
If there's a way to capture the same level of bio diversity (beneficial bacteria, critters, etc) from using dead rock, I'm game.