Well, let's see, first of all he doesn't give a rat's behind about the environment. He's thinking "I won't be around much longer, so to hell with conservation! Fish like there's no tomorrow!"
Then, he doesn't believe a two engine aircraft is safe over long distances, despite what actual, real engineers think. In other words, a know-it-all.
While I don't profess to be an aircraft evacuation expert, I can think of one reason for placing the emergency exit door on the seat, and that is to provide a clue as to the location of the exit -- when the cabin fills with smoke, it's hard to find the exit. Feeling your way from one seat to the next, encountering a door gives you a big hint as to what's there!
Of course, I'm sure Mr. Know-It-All had a very good reason for tossing out the door. Maybe so it will land on someone's head who happened to have exited the aircraft from a different exit? Did anyone ever think of that?
The missives are often provocative and peppered with expletives to get attention.
In other words, he's a spoiled, rotten brat whose social skills haven't progressed past age three yet.