It is far more important to have a site mobile compatible than print compatible which again will probably cause some HTML refactoring. So more websites are going to worry about being mobile compatible and not waste their time on print.
The percentage of people who print a site is so negotiable, that like mcmillion said you would be better served supporting IE6. This combined with the fact that print versions can not match the screen version means you'll probably never see a site embrace your rallying cry.
Your best bet is to stop killing trees and get a Kindle Paper White or other e-reader with a web browser.