Of course they want to manage their campaign by themselves without escrow service. But what doest that means in normal language?
That means that they want to have opportunity to fool all their workers without any consequences. I see such kind of action a lot of time in 2017. Too many times, specially, from russian teams. They loved to change rules in the end of the campaign, or change reward and bounty pool or change anything they fucking want!

With full control of funds it's easy to do that. At any moment in fact. With some funds holding by forum escrow it will be hard to do. You deposit for example month budget to escrow wallet, and from now at least for this month you can't fool or change rules, because there still a chance that your funds will be lost to you.

So yep, many cunning guys don't like to use escrow. They maybe don't even want to fool you today. But without escrow, a guarantee
 that you will get your money for finished work, there still a chance that they will fool you tomorrow.