I believe the title of the thread is "Amiga OS 4 should be ported over to the x86" not "Do you care about Amiga OS4 or not?".
There's a couple of reasons off the top of my head why I don't want the Amiga to be running on x86. One is that I dont really want it to be involved in the Mhz race, where only the fastest speeds will do, which is how Mac and Windows seem to be doing things at the moment. It was the same back when the classic Amiga was around. "Your Amiga with it's 7 Mhz CPU is nothing compared to my PC running it 66Mhz!".
And another point is that you cannot simply buy a x86 CPU that can be passivly cooled - every cpu, even mobile ones run hot and i'm sick of having a computer that makes so much noise. (And yes I have "silent" fans and psu in my computer, it still makes as much noise when cpu intense tasks are running)
One final point is that I dont think it's good to have just one main type of cpu out there. I think it's good to have options, and although there isn't any manufacturer that can compete with the x86 CPU at the moment, I dont think that everybody should just ditch everything else and jump on the x86 bandwagon, just becasue it's the "fastest".
It's not the speed, it's what you do with it that counts.