Pollute my minifeed with as many stupid games my friends are playing as possible?
I think you are on to something here. In my own personal experience, the amount of time I spend on Facebook has declined as it basically gets more and more spammy. I don't want half of my posts on my feed to be about what my friend just did on a game, or somebody logging their run on their exercise tracker, or checking in at some stupid location. The more stuff they are integrating into the program, the more noise it creates, and the less time I want to spend on it.
I glance through status updates on a widget on my phone a couple times a day (which doesn't show advertising), and that is about it. Maybe it has something to do with me getting older, but I don't think that is all of it. Whatever it is, it has certainly made me a user that is far less valuable now than I was 5 years ago as far as trying to monetize Facebook, and I doubt I am alone in this.