If you're alive and not in a mental institution today, then I don't feel bad judging you by the same standards as everyone else. If an 80 year old says something racist or sexist, I really don't care if that stuff was acceptable when they were 15: it's not acceptable now.
Based on what you described of your parents, I wouldn't call them nuts just based on that.
ETA:
I'd like to clarify a bit; even though I don't agree with your parents in this example, and I think they're wrong, being wrong doesn't imply "nut".
I guess I view it as a matter of degree. I think overt racism is way worse than being a bit wrong about what minimum wage should be, and while, as I said, I don't have a strict line, the line does more or less exist.
My other grandmother is the same age as my idiot grandmother, and yet she's managed to somehow not be really racist around my wife. I guess I don't know for sure what's in her brain, but at least outwardly I wouldn't classify her as a racist, so please don't misinterpret what I say: being old doesn't inherently make you a nut.
If a young person says something dumb or offense, it's perfectly fine in my mind to hold them to the same standard.
They're nutty. Other older people manage to understand the value of things and wages in the world now in comparison to when they were younger. I'm only in my 40s, I get surprised by changes since I was in my 20s, but each surprise is an update.