Makes no sense mate. Sounds like something someone who painted their car with hammerite would say to be honest.
He didn't mention "rules" he said it isn't what the car scene is into. Trends come and go, think of fashion. Years ago it was flip paint & veilside corsas. Nowadays it's Euro, sleeper etc.
People can do what they want with their cars IMO, it makes no odds to me as it isn't me being seen in it and judged, and you can rest assured that is exactly what people do when they see a car that stands out.... in a positive or negative way. If you want to make a good impression, then go with the trends, if you don't care then do as you wish. Whatever you do don't walk around with blinkers on, do something to your car that is way out there or miles behind the times and expect to get positive feedback. It just doesn't happen.
I'm one of the people that doesn't give a damn, but still judges regardless