You're basing this off a two page thread.
What he said, cept 3 page thread at this point, only by a couple of posts.
At max, you are basing this off 43 posts, which is, at max, 43 people of the Diablo 3 community. And not everyone in that thread said they wouldn't buy something. Thats, 43 people.... out of how many? Millions? So ya, a HUGE # of people haven't weighed in yet, and you can't take the opinion of 43 people to decide what the overall community of millionS would do.
So no, your RMAH won't work because of this thread isn't viable, if it reached the max post limit in say, 5 or so different threads, and each people of the 501 total posts said "No" they wouldn't buy something, then maybe I'd accept it as a decent poll, but not out of less than 50.
EDIT - Oh, and one more thing - Chances are, there will be an !@# load of people who use the RMAH and buy stuff with their eBalance they have accumulated through selling stuff. So effectively...the small amount of people who use the RMAH, will feed the larger amount, who then will start feeding everyone else. So I think you are wrong, the RMAH will work fine.