...Why is it so hard to get folks to do the right thing?...
So often, people use a sliding scale to find that 'right thing', resulting in 'Situation Ethics'.
While we are talking about fungicides and their effect on honey bees and pollinators in general, don't forget that certain combinations of fungicides and insecticides, (potentially gathered from different sources on different days), are exponentially more deadly to pollinators than either substance on its own.