Actually I think what has been described here is partly the way new computer/console/chipsets are created.
First you find out what it is exactly you want and then you build a software simulation of this to find out if it would work before taking it to the hardware fase. So what you're asking the uae developers is to do amiga inc's work for them. And who's to stop somebody to run of with there ideas since it's an open source project.
Not a bad idea if we were to live in a perfect world were people have lots of time to spend on their favourite hobby