This really seems like the exception that proves the rule, given how few Facebooks came out of that era. We had a social contract, but it turned out that being sociopathic is a winning strategy when everyone else is playing by the implicit rules. See also: modern politics.
The dominant business model that decade was monetization via getting people to fork over their data.
That's basically what Web 2.0 was.
Indeed. The 2004 chat snippet is notable because it displayed attitude that was uncommon at the time. Zuck made it mainstream.