Facebook has a history of starting with opt-in and then making it opt-out and then over time making it harder to opt-out. It is a well established pattern.
It's like the quick login feature on mobile, I enabled it once to try it, I can't manage to turn it off since then. It means when ever Facebook App is installed it will always automatically login ... So I end up installing it just when I need it.
You mean that time when "having the newsfeed app forces you to use the messaging app and vice versa" started out as forced, and then opt-out, and then opt-in? That seems like the /opposite/ of forcing people to use a given feature :P
(I see what you're trying to say, that people are forced to install two apps instead of installing one - I just disagree that having two separate apps is "forced" while having apps bundled together is "choice")