I never recline (unless there is an empty seat behind me) and firmly believe people who do are inconsiderate humans. Airline seats have shrunk to the point that people are wondering about medical issues due to restricted space.
I only fly first/business due to my height, and this is true of most passengers in those sections. Very rarely does anyone recline, and I think it has something to do with type of traveller.
Same here. In fact, "inconsiderate humans" only brushes the surface of what I consider those people to be.