Re: Just use emulation
They don't make it impossible, but you find yourself questioning why you're doing it.
Personally if I built an 8 bit micro, I'd tinker with CP/M, more useful than fiddling with a home computer. You can make HDMI 'just work' fairly easily, and USB can be exposed as serial or similar. All the CP/M (and MP/M, and others) source code is available, and the documentation is quite good.
The issue is with Ethernet, or more specifically a half decent TCP/IP stack, which 8 bit micros weren't really designed around. There are a lot of powerful embedded controllers which talk serial at one end and TCP/IP out the other and viola, your CP/M machine is on the net!
However, when the embedded controller is more powerful than your host box the question of 'why bother' becomes rather prominent. 8 bit micros just don't belong as an integrated part of the modern age. Sure, use them for a bit of data processing, serial, and other I/O, but that's as far as it goes.
I loved using my Amstrad PCW; it was a perfect mixture of productivity, pricing, and usability at the time, but it could never really compete against the PC if you threw enough money at PC software.