More often than not, I am amazed by people -- around this area we have many people buying lake lots and proceed to build a new home. They intend to nestle this home among the large, old, mature trees and enjoy their new 'country life'.
A few years later, the trees die and they wonder if some disease or insect has killed them. Well, the disease is called bulldozer and backhoe disease (my term, not UK's). What amazes me about people is they don't realize that half the tree is under the soil. And this half is equally as important as the part they see above-ground. It may even be 'more equal' to quote another.
Plant roots need oxygen in order to survive. When a dozer makes hundreds of passes over a tree's root zone (which does not stop at the drip line), the soil is irreparably changed for the worse -- compacted, compacted, compacted. With no pore space for oxygen, the roots will die. When the roots die, the top starts dying back. The tree will eventually die.
If you claim to care about trees, think about the whole tree, not just the part that you can see.