Was Nest worth 3.2 billion?

I am just a simple man, so when I heard the buyout price I thought to myself wtf are they doing?

But I realize I am not some wizened venture capitalist who sees farther into the future and potential for a companies products, so tell me, is there some great value such that nest was really worth that much money? Or perhaps was a bargain at that price?

I can't imagine it was just about some overpriced smoke detectors. Who cares, seriously, who here actually CARED about their smoke detectors? No matter how cool you try to make them, how much thought you put into them, at the end of the day they are just SMOKE DETECTORS !!!!! There is nothing exciting or cool about them, they are just some functional piece of home hardware.

So maybe it was about more than that, like google trying to break into the home sensor/automation market. But here again, was the team at nest so amazingly talented that home automation could not have been developed in house at google for a fraction of the buyout cost?

Or was it mainly about some patents? Was that the play? Cheaper to buy out Nest and accompanying patents than to strike out solo later on?

If the main rationale was the latter, that at least makes more logical sense. Because I just can't see any other rationale for why their company was worth 3.2 billion. If you can, explain it to me.