Why did Google buy Nest?

Many jokes have been made on the Facebooks and the Twitters about how Google is now tracking your temperature in your home, because they bought Nest, a company that makes beautiful, intuitive, and spectacular thermostats and smoke alarms.

The first thing I thought, though, wasn't about the Nest product/user data, but the people in the company. The Nest founders are former Apple people. Making a great physical product - not just great web products - is something of a weak spot for Google. I'm not saying that Google WON'T use the data gathered by Nest (if there even is any), but it seems to me that Google needs new designers for their Google/Motorola phones and tablets. This would be a great way to get that talent.

Of course, I could be wrong. What do I know?