Right now I'm participating in one month Twitter campaign paid in Bitcoin weekly which I'm glad I got that very limited slot. It's good for us hunters if they pay us with Eth or Bitcoin but definitely not good for the majority of ICOs. That would mean another extra expense for them especially if the campaign would take for few months. Great idea though.
Most of the Bounties will not pay us in terms of ETH and Bitcoin, i have been in crypto ICO's more than a year know but till now only a few companies paid in terms of ETH. Most of the companies will pay through their own coins.