It's a stand alone, one piece computer, like the old days.
I mean, you don't restore a Chevy Bel-Air and put bucket seats in the front, right?
Even down to the floppy. You get to thumb through the floppy case to find a copy of "Burgertime", shove it in the slot, plug in your joystick, hear the "whirr tick tick tick" of the floppy, and then MUSIC! CRESCENDO! ATTRACT MODE! AWAY WE GO! In all it's one channel, 8 bit splendor.
Pretty sure the market isn't folks looking for a bare board with cables strewn about. There is a lot of effort out there, and many folks, trying to replicate this "retro" experience. And others willing to support it.
Otherwise, yea, run a simulator on...well, anything. "Whee".
It's not my cup of tea, mind, but I'm not the one buying it either.
But don't worry. The C65 core is already being ported to MiSTer from what I've heard. So a small metal box with a USB keyboard experience isn't far away for many others to enjoy.