It's still mostly a social networking site, and to the extent "serious" content threatens the social networking aspect, Facebook has an interest in placing limits.
Lots of people have an interest in doing things that are bad for other people generally. That doesn't actually mean the rest of us should be okay with it.
> The rest of us can, but the question is to what extent the rest of us are or will in the future.
Look, if people aren't going to choose news-focused sites over social-networking-focused sites, then existing social-networking-focused sites that bait-and-switch their users into a news-focused experience are just going to lose to actual social networking sites, starting the problem back at zero.
I don't think you need to force-feed hard news to people. People who would read it will seek it out - the sorts of people who are content with what FB serves up are the kind of people who didn't read newspapers before the web and were content to get their news from daytime television.