Bounty hunters are alwasy blame for selling their tokens so quickly without waiting for the project develpment as outline in the roadmap. I don't think bounty hunters are to blame because a lot of bounty hunters hold their coins for years.
I think this depends on the case, there are indications that bounty hunters can destroy the price of tokens when they are just exchanged, but the most important role is the team and developers how they can get around and have a strategy so that tokens are not destroyed when they are exchanged.