I see what you are saying, but I maintain that for the majority of people, most will lose out. Unless I'm mistaken, that is exactly why manufacturers offer extended warranties - overall they make money!
You say that if nothing goes wrong in the coverage period, it wasn't a waste of money?! Surely it was - you've paid hundreds of pounds for nothing.
I don't entirely disagree with extended warranties, it's just I take issue with people saying it's a 'no brainer'. Just because it's only a few hundred quid, that doesn't make it good value, it just means that for most people that's all they lose.
Of course, there are always exceptions and by the sounds of it, with your past luck with VWs, it might actually be a no brainer. At the same, I've never bought a warranty and in doing so I've saved thousands...