Fiction

It can be downloaded onto a flash drive. It can be emailed. Most text-only books are quite trivial memory-wise even.

Now do the publishers and authors want you to do this? No - but they want to sell another copy to the friend to whom you loaned your dead tree too, so the harm to them is identical - a lost sale.

I have all mine backed up on my hard drive. Worries about lost/damaged e-books are minimal even without this, as since as long as the record of my purchase exists I get all the books reloaded automatically on a new device (how else would they sell you the next best model?). Try doing that with torn or water damaged paper. Batteries dying is also immaterial. When your laptop battery dies is your hard drive wiped?

Now sure it's possible that Barnes and Noble and Project Gutenberg and my hard drive and my cloud back up service ALL go belly up. Then, assuming there is absolutely no access to another computer anywhere to back up my nook SD card AND the nook itself dies all at the same time then I'm SOL. Now is that more or less likely than a house fire or leaking roof?