There isn't enough collectors, Period.
For every new collector I've encountered in the last 18 months, There has been another bow out...
Most NRL Fans can't even be asked to buy a club membership let alone spend $$$$'s year after year on cards.
I don't really think that "collectors" (or at least people like us with a specific interest) are necessarily the main target market for trading card manufacturers right now.
Certain sets are aimed at the kids' market, and that's OK, but they are also going to buy into the more expensive sets and reduce the number of high-end cards available to collectors.
Yes, the hard-core collector is a dying breed, but how many packs are ripped open by kids who don't actually "collect" and how many numbered cards wind up destroyed (by our standards).
Collectors seem to be an after-thought that keeps the industry chugging along while other markets are explored.