I imagine that this wouldn't be much different than not showing the Ask and Answer options for suspended users, which was declined. Users who get blocked represent a very small population, and furthermore are in that population for creating problems for the Community. So improving their user experience is both extremely low priority, and unusual in its own right.
But I also agree with Kop's answer, which I'll quote the relevant portion here.
It would be more unhelpful than helpful. Suspended users will be searching for the button but they won't find it; they will assume maybe it was moved or maybe they forgot where it is, and this will lead to questions via meta or emails, etc.
I believe it's important that the button is still there and that, when clicked, tells you that you are banned.
Which I agree with. If the edit link were not visible, how would you have learned that you were blocked in the first place?