I have never worked on a 6GB repository, and apart from my (pretty solid) development background, I've spent the last 3 years doing code audits for huge software shops. The numbers in this post aren't compelling.
Consider also: is it possible that the multi-gigabyte repositories this guy's thinking of are byproducts of extremely crappy version control disciplines?
To your question: I guess not. He just has a different development background. Productions like game dev or CG work require to track huge binary objects and source code in sync (I'd argue that, in these environments, any attempt to manage binary objects and sources in separate systems has eventually failed; here, source code includes shader programs, for example, which typically depend on the texture images they work on; they're inseparable. I've been there, done that)---but if you're in this industry and have managed to do it well, I'm eager to hear about your experience.
It seems that most of people discussing here agree that "Git is good for source version control, while Perforce is for asset version control". So I'm not really sure what people is arguing about.
Consider also: is it possible that the multi-gigabyte repositories this guy's thinking of are byproducts of extremely crappy version control disciplines?