Well.. that depends...

Given how often on a multi hour flight I need to get up I always book an aisle seat... (It's a medical thing)

Were I (or someone like me) to book window seats on purpose then I think that would be very selfish... It would be like: "I want to look out the window.. so it doesn't matter that I'm going to be up and down like a yoyo...you can just put up with it"

I have had that happen... and so yes, I'd agree some people ARE just jerks. It isn't always the middle/aisle seat occupant though!