Someone at the office I'm working from received a Microsoft Surface yesterday. I looked over his shoulder as he set it up, and then we played with it for a few minutes.

In the beginning, we were fully in the Metro interface. By now, even if you haven't used a device sporting the interface, you may have seen it in product demo videos or commercials. I haven't used Metro interfaces enough to decide if I love it, but it's undeniably a more interesting, modern approach than anyone would have thought Microsoft would try.

But at some point, as he was testing random gestures on the Surface, we ended up on a screen that looks like Windows on the desktop. A bit of Googling revealed this to be something called Desktop Mode, accessible from within Windows RT. I haven't used Windows in over a decade now, but the lower left Start button and bottom nav bar were familiar to me. You can run a few Microsoft apps from within this mode, most notably Microsoft Office and Internet Explorer, and you can even summon a command prompt.

Some might find this UI flexibility to be a positive. But I'm not a fan. I don't love operating system interface design that tries to stand on the border between app-centric and document-centric models, with one foot in each world. The context switch between the two is drastic, and for the average user, it's far better to reduce their options and simplify their life.

It's understandable to want to ease user groups across these transitional periods for fear of losing converts, but the shift to a new device form factor and primary interaction mode (touch screen versus keyboard/mouse) is the perfect excuse to make a clean break. Recall when Apple launched the iPhone or iPad, it didn't look like it was running Mac OS X. The document-centric model of traditional desktop operating systems was masked from the user entirely, and the new app-centric model hit the mainstream in a massive way. Apple rarely flinches from breaking from the past, whether it's in replacing connectors on their most popular devices with the Lightning and Thunderbolt ports or deprecating spinning disk/disc drives.

That's not to say Apple's hands are completely clean on this issue. In their latest version of Mac OS X, 10.8, Apple tries to get away with the same thing as Microsoft. They push in the direction of abstracting away the underlying file system, but rather than go all the way, they ended up with a Frankensteinian hybrid that I've mostly found to be frustrating. They have a Launchpad UI for launching apps that feels like an iPhone or iPad app listing UI bolted onto OS X. They've shifted some apps to the Mac App Store, but I still install others through files downloaded from the web, though Apple makes you jump through some more hoops to open some of those downloads now. In programs like those in Apple's iWork suite, they've tried to simplify document versioning with by removing options like Save As and replacing them with options like Duplicate and Rename.

Apple's problem is trickier since they're trying to shift people from one UI paradigm to another on the same device, with the same input methods. It would be one thing if our Macbook Airs and Macbook Pros and iMacs had touch screens, but we still use our mice and keyboards and keypads to interface with them.

At some point, will Apple end up with two versions of Mac OS X, one that is app-centric and another that is, like the current one, more of a hybrid? Given how high the stakes are with Mac OS X, it's possible.

But it doesn't seem likely given how they've handled their product lines in recent years. From the way they made a clean and irrevocable transition from Final Cut Pro 7 to Final Cut X to the way they've shunned the Mac Pro in favor of the Macbook and iMac lines, it seems clear Apple is focused on the mass market, the average consumer, and not the high end power user who wants full visibility into the file system in their operating system, or to install third party RAM in their laptops, or to handle audio/video sync issues in their video editing timeline by hand.

This is a shift from the paradigm of trickle down brand aspiration. I think Apple believes that model either doesn't generate enough revenue or isn't needed, or both. Once upon a time, It was cool to edit your movie on the same software used by Walter Murch (editor of The Godfather!), but Final Cut Pro doesn't generates revenue like iPods, iPhones, and iPads. Of the two reasons people used to prefer Apple products (A: it's more reliable and easier to use B: it's the choice of creative, tasteful elites) the one the new Apple is built on is A, and they haven't lost too many of the people from B though they've alienated some of them just by ignoring their desires. Many editors I knew who had shifted to using Final Cut Pro to edit have slowly migrated away again, either to Adobe Premiere or back to Avid. My Mac Pro feels like an antique, one of a dying breed.

Looking at Apple's revenues in the past decade, it's hard to argue with their focus. They've managed to infiltrate the mass market with products that still sell at a slight price premium, generating unprecedented margins in the consumer software and hardware market.

It's this market that Microsoft probably wants to (and should) target. So with the Surface, why not just take the plunge?

It's a bit of a shame, really, as in my few minutes playing with the Surface, it has potential. Rather than emulate the iPad, like some of the Google products I've played with seem to do, the Surface tries some different ideas. Without long-term use, it's hard for me to judge how comfortable the device would be to use after a protracted period, but the industrial design was solid, a cover with a built-in keyboard is useful, and some of the gestures that bring in frequently-used menus show a willingness to push the boundaries of touch-screen UI.

Fortune favors the bold, but especially for the underdog. And in the tablet space, that's exactly what Microsoft is.