Well, the thing is that Mac Pro is not meant for gaming. Sure, some people might buy one and use it primarily for just that. But that does not change the fact that it's not designed for that task. It's a workstation, and it's designed for workstation-workloads. And that does not include gaming.
you say that not including a better vid-card is a "stupid-ass" decision. to use a car-analogy, it was a stupid-ass decision by Ferrari when they didn't include a towball and a huge trunk to their latest sportscar.
That's nice. And because of that, Apple should design their _workstations_ with gamers in mind?
These GPU's that Apple offer are suitable for the intended workloads Mac Pro has been designed for. They might not be suitable for some other workloads, but that's 100% irrelevant.
Mac Pro's are not meant for gaming, therefore it's pointless to whine about lack of gaming-related functionality in Mac Pro's.
And for many people who buy Mac Pro's, it is.