I'll try to dig up the old pictures later on when I'm back home.
But I disagree with your take on the situation for a few reasons;
First, and perhaps I wasn't clear on this in my initial post (apologies if that's the case), Zon never offered to repair the crack FOR FREE even when the bass was under warranty. They claimed from the very beginning that it was a cosmetic issue and as such was not covered by the warranty, but that I could send it to them for refinishing. Furthermore, Joe Zon claimed (via an email I still have) that he had never seen this issue on his basses. If it makes a difference, I'm happy to provide a screen capture of that email. As the crack progressed over time (and after I sent updated pictures of the developing problem), they maintained that it was entirely cosmetic.
Second, to your point about maintenance and the automotive analogy...I have several basses, some older, some newer than the Zon, including a 1991 Modulus Quantum. All of them have required maintenance, as you mentioned, but none of them due to what is clearly a manufacturing defect like my Zon had.
Lets take a closer look at the automotive analogy. When I initially contacted Zon with my concerns about the finish crack (and I was concerned mostly because it made me question the long term stability of the neck) they told me that there was no problem with the bass that would be covered by warranty. They told me that the problem was cosmetic and that I would have to pay for it if I wanted it corrected. They maintained that position even as I provided them with pictures of the crack worsening over time.
Say I buy a brand new car from Toyota and when I'm driving off the lot I notice a small crack in the paint on the A-pillar. I go right back to the service department and point it out to them, and they tell me "oh that's a cosmetic flaw. it happens all the time on the A-pillar. it's a little annoying but it's not structural, and it's not covered by warranty." The crack continues to spread so I bring it back again and they tell me, once again, that it's cosmetic and not structural, not covered by the warranty. So I keep driving the car and one day as I'm on the road doing 30mph the car suffers chassis failure causing an accident and is a total loss due to the damage. If I have documentation of the worsening problem as well as Toyota's persistent denial that it's a problem at all, isn't it clear why I'd take issue with Toyota's handling of the situation? In fact, I think there'd be a pretty strong case for negligence on Toyota's part, especially if anyone was hurt.
It's worth pointing out, when car manufacturers have problems like this (especially involving safety of vehicles), there are often class action lawsuits that allow affected customers to claim damages even if the vehicles in question are now out of warranty.