I listen to almost only the Discover Weekly playlist from Spotify made for me personally. Since it only has 30 songs in it it gets boring very quickly that's why I wish a little dial or a option in the settings menu to turn the total number of songs up.
It looks like your idea was posted a while ago but, unfortunately, it hasn't gathered the minimum amount of votes to stay active in the Ideas Exchange (50 votes in the first 3 months). I'll mark your idea as "Closed - Not Enough Votes". You can learn more on how the Ideas Exchange works here.