I guess I naively thought the value of doing to others as you want them to do to you was generally accepted as positive.
It is generally accepted as positive and you are not naive for thinking so. Just because someone has a different opinion on it doesn't make you naive or the idea less valid.
As mentioned, it's the beginning of empathy and consideration for those beyond your immediate circle of people. It's general politeness and courtesy to others and doesn't need to be more complicated than that. Besides, the way some people act towards others and like to be treated is not something I am capable of or wish to be like. So I defer to just being me and do the best I can with respect to others. Somewhere along the line, common ground can hopefully be found, and if the effort is appreciated, it usually is.