In the end Nick...as mentioned above, it's all a part of the disposable society.
What is a new trend is like Air France and BA who after using A.320 for many years are retiring and scrapping but replacing them with new models which in the old days would not have happened as production runs were never that long.
Spares are a funny things
When Air Bridge were down to three Merchantmen they needed to maintain two for up to five years
The very best of the three, by far was G-APEM and that was the one that was scrapped, simply because she contained more useful spares and so gave the better chance of keeping the two other flying.
Depends how you look at it, if its a good sound machine you want then 'EM would be the one to stay, but if you are thinking which is the biggest stock of spares?, then 'EM becomes the one for the chop.
This is why some two year old A.318 from frontier were scrapped...no one wants the airframes but the spares are good for other A.320 types and the specific A.318 bits can be sold as well to the few operator that do use the type. This will add up to more than the value of the entire frame if the parts are sold separately.
Dealers can make a mint, the newer the frame and parts the more they can make
