Going back and reading what he says makes sense, but is technically not the end all, be all.
The issue is that almost all base rock you come to today is going to be dried out live rock. It all depends on what terms you assign to what.
Personally, I do not consider lace rock to be a base rock. However, IT WILL COLONIZE BACTERIA. Period. This would technically make it live rock, although that doesn't make it good for reefing due to the potential things that can leech out of it.
Bill said it very plainly. Live rock, defined as rock with colonized bacteria, can be ANY rock submersed in saltwater and given "food" WILL BECOME LIVE ROCK. Period. No way to argue it. It happens.
However, the most beneficial rock to aquarists will be rock that is very porous, thus marco rocks, homemade rocks with rock salt or what not to make the porous, etc.
Long story short, I agree with you in that the best rock to use is rock that is very porous (which I think is what you're saying). But you must realize you defeat your own argument by including homemade rock. That would be rock that has not been live before, but you say it works after saying only rock that has been live before can be live again.

Think about it.
Brandon