The question of why
We need to remember that Apple and Microsoft are coming at this from different directions not because of some major difference in thinking, but rather because of practical considerations.
Let's look at the two companies.
Apple has a small but growing Mac business. They redefined smartphones, and came up with the first usable tablet. As a result, they have very well selling products in the mobile space. At the same time, they don't cater to enterprise use of Macs. Nevertheless, Macs are now growing rapidly in business. Part of that is due to the iPhone becoming so popular in business, and government, as well as the iPad.
This allows Apple to do what it wants to do, slowly. It has the sales now. Whatever convergence they will end up with can be evolved over years, and has been.
Microsoft, on the other hand, is the business and government computing environment. It has the vast percentage of sales there, and consumer sales of Windows is a direct result if people buying, over the years, what they used at work.
But, in mobile, Microsoft has been shut out. The iPhone changed smartphones foever, and made them into the major area of growth for the industry, rather than a small 10% share of cellphone sales to business and government. This killed Win mobile, along with the other major competitors. Microsoft has not made it back from that.
In addition, Microsoft had no presence in the tablet market.
These two problems were a conundrum for Microsoft. Win Phone 7 was a stopgap measure using the old, discredited CE for a base, and went nowhere. But it was the first attempt for Microsoft to get back in the mobile race, which they, belatedly, saw as being much more important than they did at first, when Ballmer dissed the original iPhone.
But the ipad already came out, and, of course, as to be expected, Gates dissed that as well.
But as PC sales began to tremble, and then fall from increased sales of tablets, Microsoft was caught short. How to get people to buy a Microsoft phone and tablet became a major concern.
As Win Phone was doing poorly, Microsoft had a dilemma. If people weren't buying the Metro devices, how could they get them to?
Well, the answer, as we see, was to force it upon people with Win 8. In the last, it didn't really matter what Microsoft did. Even with vista, Microsoft knew that an updated version (especially after the Great Recession, which also held sales back) would mKe up for the lost vista sales. This was nothing new, and was expected, and it was exactly what was happening. But Microsoft could finally see that in the long run, that may no longer work with BYOD happening, not only for phones, but for tablets, and even computers.
So they figured that with Metro, now the Modern UI, people would be forced to use this new mobile UI, and would like it, or at least, get used to it, so that it would influence their mobile purchasing. They even announced that the desktop would eventually go away!a nd that the Modern UI would bet he future of Windows.
But why do it this way; bolting a second OS onto their primary one in a way that was so clumsy? It's pretty simple, really. Time! It takes years for a company to come up with an entirely reworked OS. Microsoft had no time. They needed to do it quickly, or get burned. So we had Win Phone 7. Really Win mobile with a UI taken from the doomed Zune HD. Why they would think that would be popular can be talked about for years. I think that one reason was that Apple and Microsoft have a major cross licensing deal in place that prevents Microsoft from copying anything Apple does in UI or usability concepts.
So they had nowhere to go quickly, and so looked at the Zune HD, and decided that would be a good base on which to build. But that was designed for a small handheld device, not a tablet, and most assuredly, not a desktop, with its large screen and keyboard/mouse. But it was what they had, and could get out quickly,
As so often happens, they were too close to the development, and no doubt became excited by it, not seeing the flaws that others saw after release.
So we have from them what we see. An OS that simply isn't suited to the desktop (Modern UI), combined with an OS that simply isn't suited to a tablet (Win 7). RT had apparently failed, so nowhere to go there.
Now, Microsoft is finding itself backing off on the Modern UI for the desktop, and just how far is anyone's guess. Where are they going to go with tablets is also anyone's guess, as even the Pro isn't selling all that well. I see estimates of total Windows tablet sales that seem well above actual sales. I only know one person who has bought one, a Pro, which he is now ridding himself of, as his employer, IBM has given him an iPad Air, which I suppose says volumes about where Windows tablets are going.
So Microsoft has found themselves between the old rock and a hard place, with nowhere to go. If they can't slip out, they will be ground to dust. It will take time, but it will happen, and devices isn't going to save them.