Well, that's because some "wax" companies call their sealants "polishes", you know, like "furniture polish". Even that M company which started as a furniture polish company 100 years ago muddied the waters with some of their glazes in the old days. Like anything, some people dip their toe in the water and think they are swimmers, and to be fair, there are people who may have been "polishing" their car for decades with stuff from the auto parts store, who really don't know the first thing about paint care, but think they do--but they are well-meaning, usually.
A lot of things are more complicated than most people would like to think they are...and in the old days people understood that. But with the internet everybody is an expert on everything, I'm sure I could find a YouTube video on washing your car with rocks...or if I can't, I could make one and get people to do it. Not that there was ever any place to get real detailing info before the internet, so I'd say we came out ok on that one.