If they pulled a MorphOS and made custom boards an option instead of a requirement, the OS4 crowd would instantly have available a broad range of significantly more powerful and infinitely more affordable systems to choose from.
It's difficult to justify the development cost of porting to out of date hardware, plus they'd be going head to head with MorphOS. I don't think the X1000 is going to work out, but Apple hardware wouldn't be a wise move either.
They need something new & cheap.