One has to assume Facebook (the company) has thought of these questions, and as usual, decided to see what Facebook (the site) thought about it. While Facebook has a history of trying to force things onto new users, they're also a data-driven company, so if things are not working, they are going to back out. I don't think Facebook risks hurting itself, since it can see itself doing so by measuring the effects of the changes they make. What Facebook risks is someone else replacing them or popular culture moving on to the next thing, which is outside of their control.