Theres more to porting it to x64 than ARM. Using the i7 as an example, you have several hurdles to jump:
OS4 doesnt support SMP, so only one of an i7's cores is used, limiting its usefulness.
Endianess will have to be addressed, when porting the OS you will have to rewrite any ASM code that may be present (If any)
OS4 doesnt support 64-bit, and since 64-bit instructions use twice as much RAM, it will be grossly inefficient
Locking the system to certain machines (like OS X is) will increase compatibility but cripple market penetration, as we are in a recession and people dont always have cash for yet another system, especiallly not an i7 system
Leaving it open to any x64 machines will cost much more manpower to ensure compatibility
Plus, AmigaOS4 has little to offer over current alternative OSes for x86. Comparing it to ZETA/BeOS/Haiku, for example, you will see more x86 native apps for it (since BeOS had only a short PPC run) compared to OS4, which will require its porting before any applications can be compiled/tested
And whose gonna pay for an alternative OS with inferior hardware support, that they have to relearn and with much less infrastructure than most other OSes on the market. The Amiga community? We are so divided I doubt you'd even get the number of current OS4 users, many of which will be angry that their hardware is no longer supported.
You seem like your mind is made up Digiman, but you know what they say, the empty can rattles the most, good luck professing your beliefs, but i feel they fall on deaf ears