I'm going to take the other side of this debate.
I think its annoying when people ask me to switch seats. Its a total guilt trip. "Would you minddddd if we swapped seats so I could sit next to my wife/girlfriend/cousin/dog/tuba?"
Its a short flight. You can't sit apart for a few hours?
I'd rather not be the d-bag who says "no" - cause honestly, I like my seat, and I picked my seat purposely. But I really dont want to change.
Anyway... thats my two cents.