When Apple dropped the floppy in 1998, that media was smaller than most files that would be copied. 1.4MB was way to small to handle raw photos, MP3s files, etc. So I think that "lucking out" had nothing to do with it. Foresight and hindsight lots.
Here we are seeing a lot of foresight. Apple has not yet dropped optical drives, but I think they are paving the way. I have been predicting it for a couple of years. It's why I have maintained that Apple is not interested in BluRay burners or even readers.
I think the switch from spinning media to totally solid state media will occur much faster than we think. As the price of Flash memory drops, soon we will be able to buy SD cards in quantities at quantities and prices similar to what we pay today for blank DVDs. Apple may use its clout with the studios who have already agreed to selling digital downloadable movies to pushing them into publishing their movies on read-only SD cards at similar pricing. If that happens, DVD and BluRay will be dinosaurs looking for the dinosaur burial grounds, with only a few years of viability left as people move over to the much more portable format.
One difference between the two: as an “electrical device”, flash memory cards would not survive exposure to an EMP pulse; optical disks (non-electrical) would.
I’ll keep backing up the really important stuff onto 2 disks, stored in cool, un-sunlit places far apart.