Look at where we were before he came, and look at where we are now.
We now have a better squad, we spend less on wages, the signings we've made since he joined have more hits than misses, we've been in profit every year (in terms of transfers at least), the Academy is showing a financial return via sales and we are performing better in the league. He doesn't panic buy either, which is of course one of the things that wasted so much money since Moshiri took over.
I don't know what else people want from a DoF in the situation we were (and are) in, but I don't think anyone could have done better than he has in that situation.