Ok, well, I'm on the side of Facebook here, I actually think its a great idea, especially with the "Facebook Chat" thing. Great way to keep in contact with everyone from back home, from holidays (got about 50 people on my facebook who I met in the States when I was over there), from frisbee teams and from various other places including university. The groups are useful (if you ignore the whole, I LOL'D AT THIS thing) for organising stuff, and my calendar is basically taken from my Facebook events - I do literally run my life around Facebook events.
I don't care about them having my personal details, either - I use a spam email address for it, rather than my proper one, so I don't get tons of emails from them. And most of my personal details are already on the web anyway from various other sites, like UKUltimate or BritDisc or whatever, or from being webmaster for a theatre company for a coupe of years. If one of the facebook staff was so inclined to use my personal details to do something (which is highly, highly unlikely), then its just as easy for them to find stuff out about me by just looking around a bit as to just take it off my Facebook details. Besides, the privacy settings are awesome, I can stop anyone random from seeing anything about me unless they're my friend, so all of my pictures/videos/wall comments/email address/etc are safe.
And, as for writing/calling people... I'm a student - I can't really afford to send letters out to people by post, my room phone has no credit on it, and if I texted/called everyone I talked to as regularly as I do on facebook, then I would very quickly rack up a huge bill, 500 free texts/100 free minutes or not. Email would be the only viable alternative, and its just a pain to email everyone on a regular basis, much easier to just write one quick status update and see what people comment about it - or create an event, to see who's coming to a party, or a group for people so I can send them all messages at the same time with a single click. Saves having loads of back-and-forth email conversations to try and sort out a party or whatever.
So yeah. I completely disagree with all that you have said. I heart my facebooks.