Reference the above and printing at time of booking... I know many who sit on the laptop in a coffee shop, office, airport etc... book, then print out later. If this were to be closed off as an option I'd agree a complete own goal... but the wording does say "re-print up to 40mins before departure".
“Ryanair’s web check-in service allows passenger to check-in from 15 days to 4 hours before, and print, or re-print, their boarding card up to 40 minutes prior to their scheduled departure time. Web check-in can be accessed via ryanair.com using booking confirmation numbers or flight details”.