I primarily "joined up" so that I would have somewhere to test out higher power transmitters legally. I'm not at all a social person, although I do enjoy some of the seminars you see at the hamfests and of course just "shopping" for parts. Hams are generally quite pragmatic, so you can pick up a lot more, say, industry-applicable antenna information at their seminars than you would from, e.g., Krauss's excellent book.
No, they aren't that much, and it's understandable when you look at just how complicated the "competition" (cell phones!) are. There *are* hams out there doing quite sophisticated work -- folks running EM simulators for antenna design, folks creating pretty fancy modulation techniques with FEC using DSP, the digital voice guys, etc. -- but it is a tiny proportion of the ham community.
Have you ever had the chance to go to Dayton (the annual national conference)? It's very much worth it, since one trip gives you a lot of insight into how amateur radio encompasses everything from, "I used to be a CB'er, but the FCC confiscated my linear and my buddy told me I'd be legit if I passed this here
35 question multiple-choice test!" to "Yeah, we're implementing some turbo codes on top of our OFDM and looking at processing with a few dedicated 32 bit DSPs or might move to FPGAs if they run out of steam..."---Joel