i don't think it has anything with believing in the future of their token because the creators of these tokens know better than you and i that their token is useless and worthless.
the only reason why they pay in their own token is because it doesn't cost them anything! if they wanted to pay in bitcoin for example they would have to spend money and buy bitcoin and then pay people. but when they pay in their own token, all they have to do is just create them out of thin air with no effort or cost!
It is still part of the believe they do not have in their project, because if they do, they should have factored all these payment in when they were doing their feasibility study before going to raise fund through ICO.
Imagine that it is a physical project and they need to any contractors for their work, would they offer the contractor token? NO, they will pay the contractor with fiat, same things is applicable to hunters too, they work for the money and I think they deserve to be paid with token that will make them have access to their salary immediately.
How can a company that is genuine want to get everything free, free fund donation, they also want to get free awareness from hunters.