Vote with your feet. Stop using Spotify. Dust off your carefully-curated collection of music files and your favorite player. Find music review blogs or internet radio stations that you like. Start buying files again. Start buying CDs again and ripping them yourself.

Spotify does what maximizes profit for Spotify, and after almost twenty years of expanding to dominate a lot of the online music space, this is not going to match up much with maximizing its likelyhood to surprise and delight your ears.