Not arguing for or against the initial point (ARM-based Macs), but there's a few things you've missed in your response.
Moving to ARM would be a huge disaster in many ways. Here are a few:
1. ARM is a great power sipping CPU but lacks the architecture to compete with x86 in performance. Having used both, there is just no comparison. Anything that is CPU demanding will crush ARM. It just wasn't designed to do that kind of work. It is a light-weight portable CPU.
I'm not degrading ARM but it is what it is. My lawn mower's engine is awesome but I'm not going to put it in my car.
No doubt that a lawnmower engine isn't suitable for a car. But there are motorcycles which do just fine using engines in the same class as a lawnmower. Not every PC has to be a 'car', just as not every PC has to be a 'truck', 'semi', or 'ore hauler'. Quite a few users would notice very little difference between an ARM-based Mac and a top of the line Intel-based Mac, as demonstrated by the number of people who get by just fine with only an ARM-based tablet. My wife, for example, technically 'has' a laptop, but it got unplugged for about a week, and the battery ran down *unnoticed* because she uses the iPad for just about everything.
2. An ARM CPU would break all current OS X applications. Sure, you could do a Rosetta deal but talk about SLOW. A slow CPU doing instruction set translations on the fly. Yeah, that will be fast.
Yep. An ARM CPU won't run X86-* software. However, software written for OS X doesn't *have* to be for X86. It can also be for PowerPC. It would take very little effort for Apple to enable compiling OS X apps for ARM, and *most* software would compile to a new Universal binary without any significant effort, because *most* software doesn't bother with processor-specific code anymore these days.
Yes, going the Rosetta route would be an obviously bad idea. But Apple tends to spot and avoid those obviously bad ideas (especially when it comes to software solutions), so I don't expect we'd ever see an ARM->Intel 'Rosetta' implementation.
3. Whether you like it or not, it is a Windows world. Windows runs on x86. When Apple moved to Intel, many people (including me) jumped on the bandwagon because I can still run Windows apps via VM or BC. Moving to ARM would kill that. The amount of people that would jump ship would really hurt Apple's bottom line.
Whether it's a Windows world or not has remarkably little impact on Apple's bottom line in the PC space. Only a small portion of Apple's PC sales go to people who use Windows. Those people would (ostensibly) be smart enough to buy an X86-based Mac, rather than an ARM-based one.
4. Intel knows that if they can get an x86 CPU to sip power like an ARM they will rule the market (price being equal). An x86 tablet that can run Windows apps as long as an iPad would dominate the marketplace.
Completely true, but it's all predicated on that really important "if" in the opening sentence, and Intel is having issues there.
5. Intel is smart and they will have a power sipping CPU well before ARM can boost the performance of ARM. Intel has the technology, the people, and the experience.
That goes contrary to current evidence. So far ARM has been closing the performance gap much more quickly than the power gap has been closing, and there's a distinct lack of evidence that points toward that changing any time soon.
Also, you can replace ARM with Apple CPU and it all stays the same.
Yep, because Apple's CPU designs are ARM designs.
This next part is entirely off point, but I'll address it anyway.
People think Microsoft is stupid because they didn't do an iPad before Apple. It is much more complicated than that. If you do x86 you get a wealth of applications that run from the start but you will loose on battery life.
If you do ARM you loose the wealth of applications but gain battery life.
So you have Surface RT (ARM) which is a failure and Surface Pro (x86) which is some-what of a failure.
People think Microsoft is stupid because there's quite a bit of evidence to support that opinion. I'll demonstrate that, using the Surface RT/Pro as an example. Suffice it to say that the CPU difference has been the *least* significant part of the Surface's failure so far.
Microsoft announces the Surface as a tablet finally done right (implying that the best selling tablet of *all time*, the iPad) is in some way deficient.
Microsoft announces that the Surface RT will be available soon, followed shortly by the Surface Pro, which is the 'real thing'. They bungle the releases of both pretty badly, and produce a tablet which is more expensive than comparable iPads (the RT), and a full-fledged laptop which is awkward to use (the Pro). Their own stores don't do a good job of explaining the differences between the two, so *many* RT units get returned because they won't run people's software.
