This is something I have never seen in MI, the chopping off of tree tops in TN. Why is this done? Some are really big trees this is done too. IMO I feel sorry the trees. But there must be some reason.

Around here, it's often because they are interfering with overhead lines... but trees don't get as big here as they undoubtedly do there. I suspect it's often just because someone thinks they're too big, and is generally a symptom of bad planning - planting a tree that's too big for its space, or for what the planter had in mind.