Why is everyone concerned about getting others interested in the hobby? As I've said before, collecting posters is a solitary hobby, it's not a team event. I don't care weather there's 1 or 1000 collectors out there, if it was only me would I stop...No, I enjoy what I do, but I don't do it for anyone but myself.
Now, if others you meet are like minded, so be it. Weather it's on a forum or in life. It's nice to have a conversation about posters with them and maybe make a few friends along the way, but this constant, "we need new blood" sounds like something a dealer would say, or are you all bothered about about not being able to sell your stuff when the time comes....? Me I've never bought for gain, and care less if I get nothing when that time comes.
I also don't care weather these so called "high end collectors" join or not. I collected for 48 years before joining here, and managed fine without them, why should I be bothered now?