Google’s Motorola buy won’t give it what Apple has

Google (s goog) wants to “supercharge” Android with its planned acquisition of Motorola Mobility (s mmi), but what exactly does that mean? Some think we’ll see Google try to provide a hardware/software platform combo to rival Apple (s aapl), but there are a few big reasons why that probably won’t happen anytime soon.

1. Buying isn’t bonding

If you’re a big company like Google and you want to expand your reach, generally speaking you turn to acquisition to get the requisite skills and intellectual property. Apple does this, too. But improving a sub-feature of your mobile OS is a world apart from taking the two biggest parts of the smartphone equation (hardware and software) and mashing them together.

Apple has been doing both sides of the software/hardware coin for as long as it’s been making devices. The iPhone and iOS were born and grew up together. Apple doesn’t make a move on one without knowing how the other will be affected. Android is fully formed; it ships on devices as a consumer-ready product. Google can’t start from the ground up to create a device and software that are literally made for each other unless it wants to ditch Android entirely and go with something new to replace it.

2. Android will remain “open”

Android, unlike iOS, is designed to be device agnostic. Device-makers can customize it to some extent (by throwing custom software like Samsung’s TouchWiz or HTC’s Sense interface on top of it, for instance), but ultimately, these efforts all have to make compromises, which is why it takes so much more processor power to achieve an experience as smooth as you’d find on iOS. In order to make sure that Android continues to work well on other manufacturers’ hardware, Google will have to make compromises too, something former Engadget editor Nilay Patel hinted at on Twitter upon hearing the news.

Google has to make sure that it keeps Samsung, HTC and others happy, and that means not introducing device-specific features that give its own handsets an edge over the competition. Otherwise, the Android-maker runs the risk of sending its greatest asset (a healthy network of hardware partners) running into the arms of a rival like Microsoft (s msft). Having to consider the concerns of outside interests means that Android won’t likely be able to achieve the same level of symbiotic integration Apple’s iPhone/iOS combo enjoys.

3. It hasn’t worked for others

Maybe the biggest reason not to expect Google to be able to mimic Apple’s success with a unified platform is that others who’ve tried to approach the idea in a similar way haven’t be able to either. I’m thinking mainly of Hewlett-Packard (s hpq), which purchased Palm and webOS to boost its mobile business a little over a year ago. Considering webOS had a tiny two percent U.S. smartphone market share according to Nielsen in a recent count, that’s not working out too well.

It’s also worth noting that the two smartphone companies who have had success with a unified platform approach are actually seeing their stars fall recently. I’m talking about Research In Motion (s rimm) and Nokia(s nok), which are both suffering big losses in market share on a global scale. Nokia’s attempts to curtail its losses actually include abandoning the unified approach with the Microsoft deal it announced earlier this year, and RIM is poking around in Android’s backyard to make up for its own deficiencies. Android, on the other hand, has seen exponential growth based on a strategy that, to date, hasn’t at all involved making its own hardware.

Money can’t buy platform happiness

Building a unified mobile platform that benefits from a tight reciprocal relationship between hardware and software isn’t something Google can buy. It’s still possible that it can make this work with time, since it has done fairly impressive things with even just with close hardware/software partnerships like the HTC Nexus One and the Samsung Nexus S, but matching Apple’s model isn’t a realistic near-term goal. I don’t think that’s necessarily Google’s end-game with this play anyway, since Motorola’s patent library seems a much more practical incentive. But if you’re expecting a Googlephone that somehow delivers a “perfect” Android experience, I wouldn’t hold your breath.