A good point. However, if, for example, the quality of the output is poor, I think that most people would not be sufficiently technically informed enough to be able to point to the printer head as the source the problem. Even if they do, there may well not be a brand sticker on the printer head. To most observers, then, it would be the printer that was faulty. Most printer manufacturers are protective of their brand images and don't want negative associations with that brand. Reasonable enough, as far as I can see. Let's face it, most branded ink or toner is expensive irrespective of brand. The best way of reducing printings costs? Probably just print less.