Giving tokens away rather than cash basically means that there is zero initial cost to the projects. If they paid in cash, they would need to use a portion of raised funds, which would then cut into funds available for other elements. It would suit some bounty hunters to get paid in cash, but I think the majority are satisfied with tokens as they have the potential to be worth more in the long run. I know some that sell them the instant they get them for market price, no matter what that may be, but plenty more hold on to them.