I like bulkhead seats, but there is no legroom in row 1 on the 757s. It was not a fair trade. You had good reasons for choosing your seat, and I think you did the right thing under these circumstances. If it were a mother and child who were separated, I might switch, but probably not if I had to accept an inferior seat.

If I were asked to make this switch, I would politely decline the offer of 1D, saying that I'd had a hard week, and I really needed the legroom & under-seat storage in order to relax and get some work done. I don't mind being apologetic when saying No to an unreasonable request, especially if I have to sit next to the person for the rest of the flight. If the other person insists on being offended, then that's their problem.