Don't forget all the work it implies. There is no point of porting it to X86 or 64 bit ARM unless you remove all the API limitations too. Like 32 bit, single core, no modern memory protection etc. That also means a lot of work. If you just port MorphOS "as is" to X86 or ARM, you would not gain much power but lose all the software we have.

It all comes down to how much work needs to be done, and what can be done with the hardware we already have.