Ed Zackly.
Apple never really supported a MacPro running Boot Camp very enthusiastically, at least to the degree that it would offer options for including sufficient specs to make a "hard-core" Windows gaming machine with the fastest gaming GPU installed at the factory. Dual-booting to macOS for other non-gaming functions, of course.
Apple's seeming reluctance to offer standard PC graphics cards in a standard PC tower chassis form-factor is the key design decision that will make or break the success of a MacPro 7,1.
To be quite honest, if I was Tim Cook, here's what I would do.
I would simply take the "cheese grater" Mac Pro design and resurrect it with a few tweaks. I would make it a standard type of PC motherboard format and issue a guideline for PC mobo makers to certify their boards are gonna be compatible and write Mac drivers etc. I would make an Apple-branded motherboard as well. You'd be able to buy whatever case you wanted, but only mobo's made to the standard of the cMP case would work in that. We all know the cMP case is one of the best computer cases ever engineered for many reasons, and so it would now be available for PC users to just boot Windows only if they wanted.
I would open source the GPU EFI code and make it easy for people to flash their own PC cards or for the PC manufacturers to issue Mac-compatible ones.
I would sell a Mac Pro already put together, but also, I'd let people build a legitimate Hackintosh without hiding in a closet.
I would make sure that every 4 to 6 months, there was a hardware refresh and that everything was price competitive with premium suppliers like EVGA, Alienware, etc.
I would court the big game studios and get them whatever they needed to make macOS gaming actually a thing.
95% of folks who want their iMacs and pre-assembled computers will not stop buying them because a BYO solution becomes available.
However, I am sick and tired of watching Windows come after the Apple market with Surface Books and Surfaces, HP Envy's, etc. whilst Apple sits on its half a trillion dollars and leaves pros and gamers out to dry.
Tim, who do you think it is, that tells everyone else in their family which kind of tech products to buy?
Apple will never chip away at the remaining Windows market or many parts of the workstation market if it keeps going with the type of non-upgradeable solutions it currently has.
I'm a lifelong Mac user, since 1984, and maybe I'm jaded, but I can't bear to see the state of things today. I can't walk into a store without feeling used, like Apple simply stopped trying to cater to what I want or need.
When I saw the iMac Pro come out, I just thought—seriously?Are there really some professionals who want non-upgradeable GPUs?