Don't understand. If you are not there then you can't use the seat. I use the sell-back system and would use it if there was no recompense. I'm not attending so I cannot use the seats. I ask friends/family and if no-one wants to use the tickets then I sell-back to the club. I would do exactly the same thing if it was just a 'give-back' though. Maybe the difference is I don't deem the seats to be something I own, as you appear to.
If you buy a membership then you own them for the season, I am not judging you as you can do as you please. I have a real issue with my club making a further profit on seats they have already profited from. I have let them know that also, of course they don't care as demand outweighs supply.