Strong dislike and I've had quite a few on long haul economy flights.
I think some pax don't realize that not all seats are equal; e.g., got asked to move back to a regular economy seat out of economy comfort or on a 777 got asked to switch to "another aisle seat" but it was the window side aisle vs. middle aisle (4x more likely to be asked to get up for your neighbors to go to the toilet...)
Most annoying one was where a mother with an infant in lap threatened me that the baby would scream all night if I didn't give up my (bulkhead) seat to her husband who was a few rows back in the middle seat.
I must admit I have annoyed other F pax after getting 2 upgrades myself...
At the same time I've gone up to a pax on a TATL flight in an economy exit row with the question "would you mind switching seats", met with great annoyance and a "uhm no" coming up, before telling them "are you sure, it's in delta one"... quite funny to see people change their mind that quickly
