The problem with the mini and iMac (both varieties) is the GPU, which is too weak for many. External GPU via TB3 is a cool idea but it’s bottlenecked compared to raw PCI-E, which isn’t ideal.

I personally don’t even care if it’s AMD instead of Nvidia, I just want stronger card options. The fact that the GPU in the top config iMac Pro is just on par with my now-old 980Ti really sours it.

Note that I’m saying this as a long time Mac user and iOS dev using a hackintosh tower alongside a couple of MacBooks.