Ever since Microsoft announced Surface RT, and before they've even launched it, some OEM's have been very dismissive about the Windows RT OS, and have declared they won't support it, either because they didn't think it's going to work, and they were going to see if something comes out of Microsoft's own Surface RT tablet (it didn't – Microsoft lost more than a billion dollars in total with it), or they were too upset with Microsoft for competing against them (such as HP and others).
Even those who did support it initially, such as Samsung, Acer, Asus and Lenovo, have given up on it since then. Now a Lenovo executive comes out and says what everyone was already thinking: Windows RT had no reason to exist.
I agree with that, but not exactly in the same way he says it. I do think Windows RT was a mistake, but not because Microsoft decided to use another architecture besides x86. No, that was actually a good idea, and in fact one of the things they did very badly is not do some kind of emulation for the legacy apps.
But even without emulation, Microsoft needed something to run on ARM, because I believe ARM is the architecture of the "future", in all computing. It's just a matter of time before it replaces other architectures in other market segments.
Now, Microsoft's biggest mistake was actually using the whole of Windows 8 (without the legacy programs support) as the so called "tablet platform". Neither Windows 8 nor Windows RT, with the Windows 8 core, make any sense on tablets. They're too bloated for be lean operating systems that can work on mobile chips, and are either slower on them than Android or iOS, or not as battery efficient.
The reason why Microsoft made Windows RT out of Windows 8, instead of just scaling up WP8, was a very selfish one (which they will never admit): they wanted to be able to ask almost as much for the tablet OS as for the "desktop OS" (Windows 8). With WP8 they are forced to ask only like $10 for the license, while they're asking $90 for Windows RT.
I'm sure at the time they thought it's a brilliant idea and gave themselves a lot of pats on the backs, but they failed to comprehend one simple thing: $90 added to the cost of a tablet is a significant price addition in today's tablet market, when you can buy a Nexus 7 for $230 and an iPad Mini for $330 (with much bigger branding behind it).
Plus, that's only part of the extra cost for RT tablets. The other cost is having to add at least 16 GB of storage compared to the competition, just to install Windows RT on that, because of how bloated it is. Even then, it will run slower with the same "high-end" mobile hardware compared to the competition.
Microsoft missed all of these issues, and they paid big time for it, by creating an OS for tablets that no user wants because it's not a compelling offer over the competition, and no OEM wants either, because it makes their tablets a lot more expensive, and not very competitive.