Digital BW, The Print

My ignorance is gonna show here but here goes. I have read all the 
posts on the list and others and I don't understand. Why not use 
duotone printing with color inks, like a selenium-type tone? My eyes 
aren't the best but I don't notice any metamerism using this method. 
The prints look fine and if you were in a darkroom most people would 
use a selenium-tone for archival purposes. I may very well be missing 
something and if I am chalk it up to stupidity or inexperience on my 
part.

Tim