Most people don't really care about having a "presence" online (if they did, they'd already have a blog out there). Facebook is about your friends and social network; your mom is on Facebook because her friends and family are, not because she has great opinions and stories to tell the world. Facebook's success has very little to do with being a platform to post things on, those are simply features it evolved into.
Although I do find it humorous you would mention profile customization as something people want or care about. I personally hated the disorganization and tacky pages on networks like MySpace.
Agreed, I think the other point is that people hardly go to people's facebook pages anymore. When I first add a friend, I might go check out their profile. But after that, it's all about the news feed and what everyone is doing at the moment. When you can comment from the news feed on whatever post your friend just put out there, why is there a need to even go to the facebook page?
Yeah, everybody looks at facebook from their own perspective, business people think it's boring because you can't customize it enought, similarly teens look at facebook as a place for teens to hookup, etc. I recently saw a post from a +- 14 year girl saying "I think people over 18 shouldn't be allowed in facebook, its gross". Hehe go figure.
Although I do find it humorous you would mention profile customization as something people want or care about. I personally hated the disorganization and tacky pages on networks like MySpace.