Creative destruction

What is the tipping point that determines when one thing (a wall or a tree, for example) should be destroyed to make room for another, presumably better, thing?  How do we know?  How do we decide?  And who gets to make the decisions?

Today, I can see--and hear--the removal of the top layer of a brick wall, brick by brick. The construction fences, scaffolding, and machinery disrupt the flow of traffic, both vehicular and pedestrian, as the noise disrupts the flow of thought.  Large swaths of trees, pavement, and buildings are disappearing to make way for something else.

Yes, there is the need for change and progress.  I teach these topics, so I know these things.  I know that backing up is sometimes necessary to go forward, that disruptive technology can also destroy, and that loss accompanies all growth.  But there is a part of me that mourns the loss of a majestic tree and questions the removal (at some unknown cost for man and machine) of a perfectly good wall.

The changes I initiate (and support) should make sense to me.  And the others?  The ones I don't initiate?  They should make sense to someone...

The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself.  Therefore, all progress depends on the unreasonable man.  -- George Bernard Shaw