DBB or any CEO can't win for losing here IMO. If DBB were making football decisions, we'd all be, properly, up in arms about how a CEO shouldn't be involved in football decisions.
It's not her fault if the football decisions are terrible. That's on the owner and his managers/DoFs (who he has kneecapped anyway). That Kenwright is such a liability is also down to Moshiri - a controlling shareholder running the team roperly would rein him in.
The stadium is on her watch - she met with us NYC Evertonians when she was in town meeting with Meis a couple of years ago -that makes her tenure a success no matter what else IMO. She upgraded the primary sponsorship - Internet car vendor > Internet bookmaker. There have been green shoots of better marketing in the Americas. All to the good. I fault her in a big way for the abysmal communication from the Club, that's within her bailiwick. But on the whole it's more good than bad with DBB.
If Moshiri had hired a DoF, given him the remit to hire a manager, a budget, and a general brief, and then stayed out of the way (and kept Kenwright etc sidelined), then the accountability would be clear. If Brands and Silva had been given the freedom to do their jobs, with the resources at their disposal (and presumably not the money squandered on Iwobi and the like) I believe that we'd be comfortably top-half and legit contenders for Europe if not already there, and we wouldn't be talking about DBB.