DVD Recorder failed discs

Hi, A very newbie basic question:
I’ve recently had 2 bad disc errors recording progs from Sky+ to Philips DVD R70 DVD Recorder. The Memorex discs used were only faulty on a small part of the disc leaving all recordings intact on the disc but no menu thus loosing all the recordings. This makes me want to revert to good 'ole VHS tape.
Why is the dvd r disc recording setup so fundamentally flawed? eg. If there’s a powercut during recording the disc is lost!
Any comments or enlightenment would be apreciated.
Cheers, J.A.