My opinion is, these cars are just getting to a point where they are not feasible to restore as labour costs just start to get astronomical and when you add this to the fact that you can buy a lot better, modern cars for the same money invested, well you can see why there are a lot of z's out there that will just sit there waiting for a revival.
That's not to say people won't restore them as a labour of love, but unless you can do (or learn to do) a lot of the work yourself, then be prepared to pay to play so to speak.