However, what I don't like is his treatment of colour printers. He somehow concludes that the only use-case for consumers to print in colour would be photos and then goes on that printing photos at home produces crappy results, so you shouldn't do it anyway. Therefore, consumers do not need to print in colour. QED.
I'm always wary of "tell me one reason you're gonna use it for" type arguments, where the asker then goes on to treat the answer as an exhaustive list of use-cases. Only because I cannot think of a use-case in that very moment does not mean a use-case doesn't exist.
For colours, additional use-cases would be colour-coded diagrams or documents that for various reasons, you just want to look pretty.