>whether you click or not doesn't change the fact that there is still ad sales happening in the background

if nobody clicks on the ads nobody's going to buy ad space because people who place ads care about whether their ads translate into sales. So of course Facebook cares, and ultimately only cares about how many people respond to them because how much money they'll make depend on how much money the ads make.

That's why FB has invested ungodly sums into trying to figure out the preferences of their users.