My understanding is they had requirements that the screen could be moved from environments and rotated while mounted, so they came up with a custom quick-releas

My understanding is they had requirements that the screen could be moved from environments and rotated while mounted, so they came up with a custom quick-release magnetic + mechanical connector. I'd think normal VESA mount holes would have worked fine as an option, especially since there has to be suitable depth with the power socket. However, I'd assume lack of extra holes to be an apple design decision sooner than assume a money grab.