> the big innovation that your profile had to be your real life identity early on.
This came after facebook was wildly successful, so not early on. I also have never met a single person who was attracted by it, or was confused as to who their friends were before it existed. That being said, tying real names to online identity allowed facebook to buy data from brokers to fill out the sliced up audiences they sell to advertisers, so maybe it was important to their profitability.
What made FB successful was that it was a platform that other developers could program for, so it filled up with games and quizzes. Farmville,
"Which Harry Potter Friends Spice Girl Are You?" etc. was all the edge that it took to kill myspace, a site which seemed to stop any sort of development about 10 minutes after launch.
But, as you say, even myspace made it very easy to write on the web. You could scribble on other people's "walls", put whatever you wanted on your own page, and every profile came with a blog.
Against what you say, however, is the timeline where you could just post random crap and all of your friends would see it and comment on it; the dopamine stream. There's no easier way to write than to spit out a random sentence or upload a random picture, and broadcast that instantly to hundreds of people.