Most of us who see a quality footballer in VdB recognize that United are at the top of the table and when the manager keeps rolling boxcars, you stick with the manager. I'm an Ole In man and I stand by my man.
It's not hard to accept that Donny may have been brought in as an insurance policy in the event we sold Pogba. On some level, that's excellent long term squad planning. Every one of us recognizes that Bruno is the better player and that Pogba is the better player. Anyone who suggests otherwise is banworthy (just kidding!). No one could plausibly argue that Donny is superior to Matic as a DCM. On his day, Nemanja is very solid, sometimes inspiring. Donny is appropriately utilized as a squad player, but the concern that has been raised here is that he's been severely underused as a squad player.
The problem arises when we see Dan James, Scott McTominay and Fred get far more quality minutes than Donny, who is simply the superior footballer to all three. There are definitely spot situations where James, McTominay and Fred are the better option, but when all three are getting more quality minutes than Van de Bee it's not out of order to ask WTF?
@Terranova made some good points above. If we're ahead, Ole brings on a DM and when we're behind Ole brings on forwards who have been quite shite for most of this season instead of an attacking midfielder who knows how to unlock a packed back line and can score when the chance presents itself. But let's look ahead as we now have a 3 point on the defending champion with roughly half the season still ahead of us. Stand by Ole, but pray that if we're chasing a goal in the second half that he looks past Daniel James and brings on Donny Van de Beek, the vastly superior footballer and attacking threat.