[snorkel]

As long as the candidate was reasonably well matched for the job and the employer felt it was at least worth talking to that candidate in person then even if the candidate is not hired then the employer still trusts that recruiter to find other candidates worth talking to. If the candidate is an embarrassment then that employer won't work with that recruiter in the future. Recruiters can tell just by talking to a candidate if they are least reasonable enough to sit through an interview and not be embarrassingly unqualified. If the candidate doesn't get an offer, then oh well, as long as the employer still trusts that recruiter then all is good. If the candidate gets an offer then jackpot. Play again.

The recruiter is only trying to please the hand that feeds them which is the employer. The recruiter only wants to maintain a relationship with each employer. Candidates are the commodity being traded, and therefore candidates are only given enough attention to ascertain their general qualifications for the job and likelihood of getting an offer.