Unrealistic setups are only as unrealistic as you make them. These so called un ealistic setups your on about may seem unrealistic to you, but to the person that made the setup, it will feel great, because they like it.
What i'm saying is when I make a setup, I don't think about all the people who would like more understeer than the setup provides, but I make it so that I like it, so that I can drive the car on the limit and be able to keep the car on the road. If you don't like using faster guys setups, dont use them, just because these guys drive faster than you, doesn't mean that their setup is faster.
'Not sure', what's the point in fixing something that isn't actually the problem? :S
Also, what's going to make it more realistic and closer? I'm not opposing the idea of the restricted setups btw, i'm just questioning the reasons.