I avoid recruiters unless they can serve me well, too (increased salary, signing bonus, etc), instead preferring to applying directly to individual companies whose mission is interesting and whose culture matches mine.

That said, I don't think hurt is a valid justification for hurting someone else, like the innocent parties I mentioned (potential future coworkers, other job applicants). That perpetuates a chain of hurt. Break the chain.

Recruiters are middlemen, and middlemen match customers with providers. For that, they get paid.

They are not "harming" either, as the relationship and deals made are voluntary.