Last generation components
The top end devices, specially the Surface Book and Surface Studio are eye-wateringly expensive, and use old tech components. How can this be a low margin activity, unless the fixed and marketing costs are out of wack?
Show me a Surface Studio user who wouldn't like to have a second matching monitor. Yet where is it?
Why cripple the processors with too few cores? And can they stream 4K films/TV that is protected? DDR4 memory? Thunderbolt 3?
There is other stuff missing too, but detailed specifications appear to have been removed from the MS web sites.
Why they didn't design it to use the the next gen hardware and release once the components were generally available, is a rookie error.
If a user needs a top end workstation or ultrabook, it is almost guaranteed that the user will need more than one screen. Even spreadsheet jockeys need multiple screens.
Maybe marketing types are unaware of this, MS appears to be completely overwhelmed by them.