But now that I am more established, I doubt that I would apply for positions through recruiters. However, it can't hurt to have them looking around for you, too. The main thing to remember is that legitimate recruiters never ask you, the potential employee, to pay anything.
Legitimate recruiters receive fees from the company that is conducting the search.
I wouldn't trust any recruiter who claims to have contacts in academia. It's an overcrowded market, and most academic institutions simply don't have enough money to spare to hire recruiters. The legitimate recruiters that I know about operate in private industry. I think the answer is that academics are too rude. Because search committees are accustomed to having the upper hand in the job market, they don't feel the need to correspond professionally with applicants.