It's strange they're surprised he's only 23. It doesn't surprise me. The facile "you suck" is the hallmark of the Beavis and Butthead 15 year olds on Digg.
Enough to get the formula. Rush Limbaugh uses the same one. But oddly enough Limbaugh is the more intellectually honest of the two, because he's not attacking things where the right strategy is to launch with a minimal version 1.
I think uncov is critical in a reasonably intelligent way -- albeit they use humor, rather than sombre critical analysis. The things that uncov typically makes fun of startups for -- being derivative, lacking interesting technology, not providing value to users, not having a workable business model, etc. -- are substantive criticisms.
It would be surprising if he was 30. Tearing down other people's ideas is easy - it's actually what some people are best at right after graduating from college.