Exactly. I don't care if the government knows when I'm home (they can already figure that out), but imagine if Google's database of Nest info got leaked.
Burglars could look at the database and say "Oh hey, look, no one's home right now."
Calling that a Google data breach is a pretty big misrepresentation; keyloggers installed on user machines collected passwords typed into a number of websites, including Google's.
(disclaimer: I work for Google, have no special knowledge of the incident in question)
I guess that the threat of being abducted by aliens is higher than burglars successfully hacking Google to get information on when you are not at home.
Burglars could look at the database and say "Oh hey, look, no one's home right now."