Might have a lot to do with the relative state of infrastructure and, generally, their surroundings.
That is, you might be personally fine off economically, but you're seeing abandoned buildings all over the place, the trams are run down, and the schools have leaky roofs because the municipality has no money because half of the population moved west and all the infrastructure is oversized.
Meanwhile, the stereotypical Green voter is living in a city driving their Cayenne to the horse pasture enjoying the quaint surroundings. (I mean of course you need an SUV you're towing the horse once every two years)