Mothers, eh? You literally couldn't have lived without them. And if there's one thing that's true about mothers is that they're people.
Spotify, though, isn't aware that mothers come in different shapes and sizes. They seem to picture them as confused old people who might struggle with the very idea of music streaming:
To be fair, my Mum would take a lot of catching up if I had to explain streaming music to her - "right, here's what's happened since 1983; maybe we'll start with compact discs..." - but most mothers aren't going to be befuddled with the idea of digital products. Most grandmothers wouldn't be, either. And those that are (along with men who are) are probably not stupid, but just uninterested.
A bad move by Spotify. Unless 'insulting your customers' is a cunning business strategy.