There are a few problems for farmers - remember you cannot eat coal. Where do you think food comes from?
Main issues are contamination (eg salt water) and mining assets that destroy the ability to farm the land. These are long term issues...
Basically:
How would you like it if your $1M-$1.5M property was turned into a $50k property with $150k compo from the mining company?
and you wonder why they complain...