Who said bounty hunters are guilty? Bounty hunters are not lowering any rate at all, if anything, they are generating additional exposure for the ICO so that ICOs are likelier to succeed. Besides, if giving out bounties were not profitable, ICOs wouldn't be offering them in the first place.
I believe that bounty hunters are just doing their job. They are advertising the product and therefore deserve their intended bounty as well. If should it be true then it should be planned well since advertising is really a good part of a business exposure as said that is why I could agree with you.