Hello fellow player,
Possibly a good idea, I have had the same thought a number of times. The problem though is that you would destroy a part of the game in terms of planning. If you need carriers for a while and after that they have no more use than perhaps you should not build them in the first place. It is part of the game's overall strategy.
On a different note this would mean that players could just give up on maps. If someone would feel like they could not win they could just descommision all their troops and then leave the game. The problem here would be that the 'stats' feature of the game would be nearly useless since everyone could have an artificially high rating.
Kind regards,
Edepedable