If the bounty hunters get the rewards from bounty with ETH, it will minimize the risks for the bounty hunters when the token has a low price after ICO.
But there is always a tendency for bounty hunters to dump their tokens once they hit the exchange and it will affect the price negatively leaving investors very sour and bitter.
But if bounty hunters get paid in ethereum then they won't have to dump the tokens from the ico project and it will allow the investors to rest easy with the listing price.