Why blame bounty hunters generally? there are a lot of stakeholders in this market or in every project, and all of them are potentially able to cause the dip.
Also as been stated by Numanoid, bounty allocations distributed to hunter are not that representative of the most part of it.
bounty amount aren't too big (mostly it's 1,2, or 4 % from total supply).
Early investors, who bought token at private and pre-sale with big bonus causing that. They dumped all of their token including the bonus on market
So I believe all are liable and potentially suspect. Not just bounty hunters.