When there's nothing for one to compare against their current situation, whatever state they are in is satisfactory.
However, once there is something contrasting, one naturally starts to compare.
Is it better there? Am I happy here? Can I do better there? Will I climb higher here?
Their environment looks good. The people here are terrible. Their department are so bonded together. The atmosphere here is too stiff.
Grass on the other side always look greener. Isn't it?