I agree, monotone printers are available technology, and monotone printers have worse output quality than a color inkjet printer.

If you want a monotone printer, buy one. I just have a little bit of confusion around the situation where people who bought color inkjet printers aren’t willing to put color ink in the printer.

You’re aware, aren’t you, that a color inkjet that only squirts ink out of the black cartridge is, technically speaking, a black and white inkjet printer? A color inkjet is literally a superset of a black and white one.