It is not impossible for bounty hunters to be paid in other currencies like BTC and ETH. There are sections on here you can get such jobs and they are open to select ranks. But I feel this not feasible for most ICOs to do considering the number of bounty participants they get and it will not encourage the circulation of their tokens
That's right. There are actually projects that give Bitcoin or Ethereum as their payment method rather than their tokens; however, those projects are very difficult to find because most of the projects these days are trying to create their own coins and ride the cryptocurrency wave. Also, the requirements to enter those projects are very difficult to reach; the sheer level requirement is not that issue to comply with. Of all my years joining bounties, I have only joined one project that paid in Ethereum, take that for rarity.