I do believe many left-wing voters (around the world, but especially in this country) secretly hold serious contempt for rural areas, their lifestyles, and their values, and therefore see any sort of negative development in rural America that pushes it’s populace to urban areas as a good thing, where they can accept urban, progressive values.
A few things here:
1. You can have contempt for someone on a personal level, and still want to ensure that their material needs are met, because they are fellow human beings.
2. Urbanization is a good thing in and of itself, for economic and climate reasons, and has nothing to do with cultural issues.