I appreciate that electronic copies of a given medium--be it books, music, movies, or what have you--are more ecologically friendly than their traditional physical counterparts.
However, I regardless still like to own those traditional physical copies, to hold them in my hands, place them ordered on a shelf for show, etc. I'm also more confident that I'll be able to enjoy those physical copies at a whim for quite some time to come, whereas digital copies bring with them fears about Amazon deleting all of the eBooks I've bought for my Kindle, my hard-drives become corrupted, etc. (Although I suppose that a fire or flood could hypothetically wipe out my physical libraries.)
Beyond even all of that, I prefer taking a break from the modern world by turning all of my electronics off and enjoying a well lit physical, paper copy of a book in my hands--as opposed to turning my attention from all of the other glowing rectangles that I've been staring at all day to stare at yet another such screen for yet another hour! At day's end, this tradition route actually helps me wind down and prepare for sleep--something that a monitor's artificial light would probably not achieve.
Of course, this is all a matter of subjective preference.
If we should reach the point that traditional printed media is no longer feasible within my lifetime, I'll gladly switch over and join the 21st Century's digital revolution!