It's a phrase. Not only is it a phrase - it's a phrase with two numbers and a goddamn decimal point in it. If a phrase with numbers in it can suddenly be a word, then I would like to make a case for "2 Legit 2 Quit," "lonelygirl15," and "Highlander II: The Quickening."
2. It doesn't MEAN anything
One of the things about words is that they're supposed to mean things. It's why we have dictionaries. Web 2.0 is something that you say at marketing conferences in, like, 2004, so that the other marketing professionals from the early 2000s will give you their business cards.
3. It makes people from the Internet look bad
It's already embarrassing enough trying to explain to my parents why Keyboard Cat is important when they ask what the hell I do for a living. Now I have to explain to them that the Internet is not actually the Internet but in fact "Internet 2", which is exactly the same as the original but different. Kind of like "2Fast 2Furious." Which now that I think about it - shouldn't that be a word?
4. The other candidate was going to have been "n00b"
I'm not kidding. That would at least have been hilarious. 'Cuz, like, when grownups came up to me and said, "Please, sir, could you tell me what is a n00b?" I could have just said "Look in the mirror, n00b." And then punched them in the grundle.
5. It will only encourage them
Now that they have been officially validated, the bastards are going to start saying "Web 3.0." I just know it. And then where will we be?