In @Scott's answer to this question Best format to save Photoshop artwork for printing?, he states that most home printers will more accurately reproduce the colors from an RGB image than a CMYK image.
However, all of the inkjet and laser printers that I have ever used at home use CMYK inks/toners. So, I would think that using CMYK colors would result in more accurate color reproduction.
Assuming Scott is correct (and based on his reputation and profile, I completely believe he is), why would printers with CMYK colors be more accurate when converting from an RGB color profile?
After reading the response mentioned in Scott’s comment, I want to clarify what I am asking slightly.
Why in the heck doesn’t a printer that uses CMYK simply use the percentages of each ink as specified in the file that it is printing? Assuming I could configure my design software and monitor to match a (hypothetical) color profile provided by the printer manufacturer, it would seem more efficient for the printer to simply use the specified percentages for each ink color. So why doesn’t printing on a desktop printer work that way?