Yes...but I'll say it for a third time - you spent 50 points on the special ability.
If you had spent those 50 points on his quality, he would have increased by about ~ 500k
Your players have lost value and you have had nothing to show for it in terms of player quality.
Players lose value as they get older, it happens in real football, and it happens in Top Eleven. If you're not happy with that then you need to possibly make a suggestion to the developers. Every other player has to deal with this in the game and it is all part of player management.
If you train players effectively, you can still make a profit, and also get more seasons out of them.