I have read the posts. I've also flown over 100K miles this year (and moved a couple of times - not asked very often). I agree that someone travelers try to take any advantage that they can and/or are unwillingly to help others in any scenario), but I put the passive-aggressive parents (or grandparents) on that same list.Have you actually read previous posts? People who refuse to swap until left with a screaming child, people who fake an invalid status, and (not above but I witnessed recently) - people who buy early boarding for one person in a group who boards and throws a briefcase on one seat, a jacket on another and a carry-on on a third to save seats for the rest of the group. I'll take my passive-aggressive!
You keep your passive-aggressive and I'll keep my seat.
ETA - none of your examples are actually applicable in your story anyway, as you were flying an airline with assigned seats.