I think the quote above has little to do with GPS. The crucial bit is:
The lesson learned is how important it is to be ready with back up navigation. Also; since ATC is there to help; I should have asked for vectors.
He could have been tracking a VOR or NDB when the receiver or ground station failed. Same result. No back-up plan(s). THAT is the real issue behind many incidents/accidents. Loss of situational awareness.
Today's GA terrain/airspace/weather/fuel/airport aware 2 & 3D navigation kit is superb. Far in advance of anything you'll find in a commercial airliner and in my experience, probably more reliable! You still have to have options for when the screen goes blank, though, whether you're straight back to DR or have a pocket GPS or lower grade stuff in the panel. ATC are there to help, plus if you've had multiple failures, D&D on 121.5 is available. Handheld radio, just in case? Cellphone and squawk? Etc.
As I pointed out a few pages ago, in the not-too-distant future, most conventional ground-based navaids will have been withdrawn from service and navigation/charting information will only be available in electronic format. Time to get with the program, as they say...