Not that the people who like listening to it mind terribly, most of the time; it’s useful to have a code word that means “this is your sort of thing.” But what sort of music isn’t ambient, given the a decent stereo? Merriam-Webster has the word meaning “existing or present on all sides: encompassing,” which is to say that the word refers more to the way in which a sound (or, say, a breeze) is present, not to the nature of that sound.