95% seems like quite the hyperbole. For sure there are plenty of n00bs and unprepared cars, but I don't think that those are the majority of cars, at least not at the races I've driven in.
There's three tiers of cars at events (I'm stating this for the edification of the thread, you are clearly aware): under-prepared cars that usually go down in flames, sorted near-stock cars that reliably bang out laps that pursue the tortise side of endurance racing, and sorted modified cars that pursue the hare side of endurance racing. These can turn the fastest laps but may have lower reliability than near-stockers. Well, I suppose that there are really 4 classes, the final being the cars going for IOE. Hehe.
Driving in such a varied field is a lot of fun. Reading traffic properly will give you a significant advantage over other cars in your class. Understanding the performance differences between all of the cars lets you drive intelligently. You'll always get a number of laps with an open track in front of you to exercise best-practices on the racing line, but you'll also have to get good at driving off the racing line. The best part of lemons is going toe-to-toe with a car that has wildly different performance characteristics than your own. One of my favorite times was driving a mostly-stock MK2 MR2 against a turbocharged crown victoria. I had absolutely nothing on them in the straights, but managed to get past them by out-braking them and reading traffic well.
I've said it before, and I'll say it again: different people are looking for different things when they get behind the wheel. Some are looking for inexpensive track time, some are looking to be better drivers, some are looking to win, some like to think they're training to become a pro driver. Lemons/Chump offer a certain experience, but they are neither inherently better or worse than other options, just different. To think or say that there aren't competitive cars or drivers in any sort of racing is simply ignorant.