Yeah, it's all about maintenance. And these things are so damn easy on that that there's no excuse for negligence.
Take care with the mix, use good products, and clean up the rings/grooves and other carbon buildup every season (or twice).
It's a one hour job on these things once you get the hang of it.
Still though, it's a matter of scale. I expect that I'll eventually get 100k plus out of my BMW without major work. If I drove it at highway speeds in second gear continously (basically what I'm doing with my Puch) I'd just have to expect a lot more trouble, a lot more sooner.