But it doesn't change the fact that airspace is being denied not due to traffic factors but because an organisation which has control over it doesn't want to spend the cash to proved the resource to allow it to be used.
If it does want to spend the cash revert the space to uncontrolled at the times its not used. Maybe not the whole of the airspace as I presume some of it will be used when required.
But to refuse access because that area has been allocated to another controller and they would be overloaded with VFR traffic in it isn't really playing the game with the access if safe principle of class D.
It is more than safe VFR traffic being there and it won't compromise IFR traffic. So apart from it costs money what's the reason to exclude the VFR traffic? .