It is so bad to think about that, you work, you put your hard assets, time and effort into it, and after a year or more, the worth of your efforts are diminished.
Why is it legal to diminish someone's effort? I mean if someone pays for it, it means it worthed for him to pay that thing. Then it means it worth that much.
Why does someone has the power to say, no, it does not worth that much.
It is like, you buy milk for $5, and then I say to the shop owner, no, your $5 worth from now on $3. ????