It does feel like MS just shows up like that. Azure did (and does) give that impression; Zune, as well. And Surface tablets are also a clear response to the iPad (whether MS ever had anything in R&D previously or not, they certainly didn't ship).
But I think Google is much more prone to jump in to a market with force, they just seem to execute "better" (I leave that open to interpretation).
FB comes out and MS buys in whereas Google makes their own social network. Apple makes the iPhone and Google makes Android. Only much later (as the ship has already left port) does Microsoft come in with Windows Phone (I'm only considering 7 & 8). Somewhat related, I feel like MS and Dell were on target with the Axim from a product idea standpoint but Apple really capitalized on combining the functionality of a phone and forward thinking hardware and software design with iOS devices.
That's because that has been Microsoft's strategy from the beginning: let someone else take the risk of proving whether a market for something exists, and then, if it does, get in there quick with their own offering. They got into the PC OS business with MS-DOS after the Apple II; into the GUI business with Windows after the Mac; into the word-processor business with Word after WordPerfect; into the browser business with IE after Netscape, etc.
Maybe I'm being pedantic, but I don't believe that was true for the BASIC through beginning MS-DOS era. Putting a BASIC interpreter on the Altair 8800 and other early microcomputers was an "obvious" thing to do at the time given the language's popularity in minicomputers, and MS-DOS and its wild success essentially fell into their lap, with their critically being willing to bet the company on it (DRI, the CP/M company wasn't willing to do business on IBM's terms, hardly surprising at the time) and successful execution.
After that, yeah, a lot of following, then again for the GUI introduction era everyone was following Douglas Engelbart, and Xerox PARC for the graphical part.
I'd go so far as to argue that it really wasn't the same market - the one that Windows Mobile was in was not anything like the smartphone market created by Apple and Google.
Tablets, you can make a case for, as above, I guess, but again, the leap with the iPad was so great that it wasn't just an iteration but a leap, leaving it open for a fast follower to come on (as Google did there too).
The difference I was trying to point out was that Apple and Google had no legacy involvement in the market at all. Microsoft had clearly defined strategies that were playing out, and were working on developments to further those strategies.
Apple and Google didn't have Windows Mobile 6, 7, and 8 being planned and developed when iOS or Android were released. Microsoft did. It's slower to turn a ship around than it is to start one going in the right direction in the first place.
And besides faster processors and a slicker UI, what exactly puts Android in a different market than Windows Mobile? Serious question. Both allow you to develop, download, and install apps. Both are pocket computers with a cell phone built in, built on the same paradigm that Microsoft ushered in throughout the 90's (give users almost complete control, let OEMs do whatever they want on the hardware side). Windows Mobile has touchscreen support. Both can/could be gotten for very cheap or very expensive. Android seems to be, for all intents and purposes, a straight-line evolution of Windows Mobile with a Linux kernel (yet still closed-source where it really counts).
Android and iOS are effectively in a different market than the original Windows Mobile because they were designed from the ground up to be used only with fingers on capacitive multi-touch screens. Same thing with the tablets. Windows was designed to be used with mouse and keyboard, which is why it never really worked on tablets. Windows Mobile seemed more like an attempt to make a phone as much like a Windows PC as possible, rather than a genuine rethink of how people would interact with mobile devices. Windows Phone seems much better, but it looks to be too late to get a foothold in the market, even with Microsoft throwing money at it.
What puts them in a different market now? Nothing.
What supports my claim that the market was created by Apple and Google? You cannot exclude "faster processors and a slicker UI", as you put it - nor what they're a part of. It was a revolutionary change in user experience.
Your point about neither Google or Apple having involvement in the industry is a good one and it's not completely uncommon for stories of disruptive innovation - which this clearly is...
I didn't say they were executing on that strategy well these days. Surface, Zune and Bing are all examples of fast-follower products that either came too late to be relevant (Zune) or that weren't good enough relative to the competition to displace them (Surface, Bing).
Which is not to say they can't execute a fast-follower play successfully anymore -- see XBox and Azure. Just that they don't nail it as thoroughly and consistently as they used to.
Agree with G+ being FB inspired. There's more to it (Google ecosystem etc.) but I'll leave that.
Android, however, was totally unrelated to the iPhone. In fact, Android's development started before the iPhone. Android's inspirations were also totally different. It's just that the iPhone appealed to a larger number of initial users and thus gained market share quickly, because, well that's what it was designed to do.
Azure wasn't so much "Amazon has EC2? We should have our EC2 as well!", Azure was one of the few products Microsoft actually succeeded in launching. Otherwise, Ballmer greeted Microsoft with a series of failures...only when Ballmer has no control does the company actually succeed.