Raph's idea seems to be that RMT is simply another ancillary service that can spring up and provide revenue around the MMO market (of which this very site you're reading is one). But there is a serious difference between RMT, and services like the one this site provides (in the form of MMO news and guides). RMT is still, among most players, considered cheating. As most people trying to make money off of RMT have pointed out, it's a cultural thing, much more ingrained among Westerners than anywhere else. But it's still a perception that exists-- it's OK to look at a strategy guide to become a better player, but it's not OK to pay real money for better gear.
Which makes Raph's last two sentences that much more disturbing. He says gamers won't like this (and they already do not). But he says that the same people who publicly decry RMT will be spending money on it in private. As much as players argue against RMT on message boards and in blog comments, there's no denying that these venture capitalists are convinced there is a huge market there.