An interesting thought.

Well, I guess we dont want to rush into this and make sure we really know what we are doing before we hit delete button on some areas.
But I have to admit, there is a cerrain charme to it and I can see some pretty unattractive areas getting a nice upgrade that way.

Perhaps we want to start carefully and experiment on a small area before we approach big sections of land.
There is a small mushroom island at -5300, -100, which nobody really seems to use.
Also, I could imaginge that some of our other islands with inhabitable climate (-1600, 3000; -800, -3000 or 3800, 2600) could sink below the ocean and resurface as new landmasses without risk of loosing anything.

Just a thought - like trying out a new polish in an un-obstrusive spot, if you are not sure that it does not damage your expensive surface material.