Rabbits living in human-populated areas eat vegetation that is likely to have been treated with chemical fertilizers, herbicides, fungicides, insecticides, and other pollutants. Their meat should be treated as potentially toxic biological material, not as a food source.
Incineration is the only safe way to dispose of toxic biological material. All the Swedes are doing is converting some of the energy released during incineration into a usable form instead of having 100% of it go up the smokestack as waste heat.