I'd like to chime in on this subject....
Before I got into crawlers, I owned a Slayer. It started as just a basher, but I quickly realized I wanted to be competitive and get into racing. I had no problem throw money at the hobby. Went to my first event. Truck had plenty of problems. Local guys came over and got me up and running in minutes. But the real problem wasn't money, or support, but my lack of driving ability. I couldn't connect jumps to landings, or judge distance to keep the truck on the track. People were there giving me advice, but it was of no help. My own ability as a driver stopped me from ever doing anything more with it. Hell, maybe I was as interested as I thought I was.
What am I getting at?
I don't think spending is most peoples issues. Used trucks can be had, and its not terrible to get a basic starter rig.
I don't think a lack of help is the problem either. Every event and clubs event I've been too, has had people that wanted nothing more then to see each other succeed and beat each other.
So where's the problem?
I have a feeling a lot of people get into the hobby with nothing more then a slim interest. It looks fun to them and easy. A few courses in they realize its not at all easy at first. Same way I went into racing and just shy-ed away. I suppose making courses easier would help keep the initial interest, but if they no want to learn how to drive and understand the truck, they'll never be in it for the long haul anyways. Most just want to point the truck and hope it makes it up the climb.
Another key factor, is the average joe wants to go out to a LHS and buy everything they need and want. Most don't dive into a community until they decide that they're 100% interested and want to stick it out. It's not easy to find the parts you need for crawlers and there's so many choices, it is beyond overwhelming. Then they must contact numerous different vendors in order to get the parts they want. Can be daunting and a hassle, especially if you don't know who to contact.
And for those dealing with decline in numbers, I can totally understand this. Our club has declined dramatically, in the past year or two. I think a big reason goes back to the same reasons as above. The big pros are pushing the limits. They drive, practice, and comp numerous times a month. The declining members were only once a month or so comp'ers. So without the constant driving practice, its frustrating trying to keep up from just a driver stand point. A lot of these same guys don't know how to keep the trucks cutting edge. And they thus find themselves, overwhelmed thinking that because they don't have the latest and greatest, they can't keep up. That's simply not true at all.
Everything comes down to practice, practice, practice. If you can't get the new guys out practice, they will never become a good driver, and never stick around the hobby.