Why does playing one song queue the whole folder or album

I’ve never understood why this is the default behaviour. I mean if I’m trying to start a single song as the beginning of a playlist I have to click on the song then go back and remover the rest of the album/files-in-folder before i can move on….

By now I’ve just learned to deal with it. But I still would like to know why it defaults to this behaviour (and has seemingly no way to change it).