I disagree. Dumpster nailed it:"....right the first time." for this particular aircraft.
Liability attorneys and government regulation DID almost wipe out GA (General Aviation.
We're only just now seeing new designs (Sirrus, Liberty, Light Sport, etc etc.) and features.
What's being celebrated is that, thru time, the 172 has delivered in consistance of performance, flight characteristic predictability, and in a cost-effective fashion.
It's been an evolutionary aircraft; improvments made every year.
~GCR~
The 172 does what it was designed to do very well, simple as that. I've got a few hrs in them, from new ones, to some old abused beaters that should have been grounded. I got where I was going safely, and most of the time had fun enroute.
I was on the C-172/Porsche conversion project, back in the late 80's. What a pain. The project was a success in getting the STC, but it was heavier (which resulted in a lower payload), much more expensive, and more complicated, which means more maintenence (although the engine is very reliable). Sure the Porsche engine is great, but potential buyers looked at it and said, "with that price tag, I can get a nice C182, carry more and go 20 kts faster". So upon getting the STC, Porsche shelved the project.
I've been away from flying, or even hanging out regularly at the local aerodrome for years, so I don't know if Porsche has since decided to offer the C172 conversion again.
I agree GCR.
But when they eliminated the depreciation allowance to write off an item such as a business plane (it was a 10 yr write down if my memory is correct) that also caused production numbers to go down dramatically. No one ever talks about it.