Yobit panel for payout is thousand times better than manually check, counts and send. Moreover the campaign budget is huge per week (~5 BTC +), current campaign manager is trusted to us with holding this amount (I believe Yahoo will not run campaign if the project owner hold the fund), but may be admin isn't getting trust on him with this amount. That's why Yobit has been chosen.
I'm not 100% confirmed but this is what my observation is.