It depends on the demographics of homeowners and the amount of income spent on electricity. People with children, especially small children, have a higher electricity bill. People with grown children don't and are likelier to have money to invest into a PV installation on their roof, which they are likelier to own.

most people are prepared to pay slightly more for renewable energy

Except those who can ill afford it. That applies mostly to poorer families with multiple children. That makes it sensitive.

There is no need for it: wind and solar are driving the prices down

The causes are debatable, but the prices are clear. Electricity is becoming more expensive in Germany to household consumers.