They're probably the same people who only want to know where the power and the channel up/down buttons are.

GregoriusM nailed it, it hardly matters what the symbols are, if the customer has so little experience with A/V equipment they don't know the stop, pause, FF, and rewind symbols ... there's going to be a lot of things they'll need to be taught (or learn) if they want to actually take advantage of their fancy equipment.

Now if they'd rather pay someone to tell them what a button does then to ask a child, ask a friend, or *gasp* pick up a product manual ...