The "mass protests" show about a thousand people in Terminal 1 every Monday. Compare this to the 140.000 passengers passing through FRA every day and the amount of people affected by airplane noise in the Rhein/Main-area (probably millions).
A small, but very loud minority dictates the policy nowadays. Unfortunately most people donīt care, even if their job depends on the airport.
FRAPORT offers to buy houses most affected my the noise. Interestingly, a lot of people sell their homes only to rent them back and stay where they are.