Wikipedia itself defines 2.0 as social. What you call social is the commercialization of social (algorithmic social?), that might be how it's understood today, but then the main idea was user generated content, at least that's how they sold it. But yes, they also used "dynamic vs. static" that, like I wrote in the previous comment, was already in use... it's like they were conflating everything new and good vs. the old and bad. Actually it was very confusing, round corners...
almost is right, no wonder they've chosen 3.0 to sell this new gold rush.
Edit: I'm afraid I'm taking for granted that people remembers this, but it's possible that a good portion of you weren't even born. Web 2.0 was something like "you should adopt the Web 2.0 ways in your web presence" being sold to all kind of companies. You have an online shop? You should include a support forum where users can share their experience with your products. In other words: a "web page" is not enough, you need the whole pack. Sometimes it made sense, sometimes it didn't. As with many of this trends, it used to sound a little cult-ish at times.