> I see very little possible misuse of temperature preference
Imagine that the season is changing where you live. You could be expected to start shopping for warm clothes. Google can easily show you ads for pricier warm clothes, and move organic results to page 2. Or Google knows you boiler broke down. And shows ads of pricier service companies instead of the lower-priced local fixer who is now on page 4. The immediate harm is that pricier alternatives are pushed to you, and you don't even know that cheaper alternatives exist, because Google controls your entire world.
First, somehow I don't think Google is going to do this. This is a company that keeps a multimillion dollar liability on their front page (the "I'm feeling lucky" button) out of culture and deference to tradition.
Secondly, what you suggest really isn't even misuse.
Imagine that the season is changing where you live. You could be expected to start shopping for warm clothes. Google can easily show you ads for pricier warm clothes, and move organic results to page 2. Or Google knows you boiler broke down. And shows ads of pricier service companies instead of the lower-priced local fixer who is now on page 4. The immediate harm is that pricier alternatives are pushed to you, and you don't even know that cheaper alternatives exist, because Google controls your entire world.