Hasn't anyone noticed that many Facebook users will friend everyone and anyone who asks? This suggests to me that they either do not care about privacy much or, more likely, don't use Facebook status updates for intensely private information.
No. The people who friend everybody are not real Facebook users. They are generally older people, already out of college/grad school who are unable to build a true network of acquaintances on Facebook and are just on Facebook to feel as though they are participating in social networking. Twitter is a more suitable option for these people because it doesn't require any genuine social interaction. Real Facebook users have hundreds of photos and thousands of wall posts accumulated throughout the years (of college). For them a Facebook account is actually an online profile of their actual lives. Most will want to keep this private.
And nobody cares about status updates. They're generally just an inane sentence about whatever you're doing. But isn't that all Twitter is? YES! Twitter's entire function is just a minor feature on Facebook. But remember, Twitter's purpose is to allow old people who can't make a real social network to delude themselves into think that they're on the cutting edge of technology.
You see this a lot in the mainstream press, some journo saying "what's the point of competing to see who has the most friends" or "who cares what some random people are up to" whereas in reality, no-one who is what you call a real user even thinks like this.
It is also true however that FB wants to cater to that group as well.
