There are good trees and bad trees. The bad trees are nothing more than overgrown weeds. They seek to strangle the good trees, and steal all of the nutrients from the soil. Unlike the good trees, they don't add anything of value to the ecosystem. They are thieves. But the roots of the bad trees run just as deep as the roots of the good trees.
It's not enough to simply cut off the bad tree at the trunk. You have not killed it. You have only made it smaller, less of an eyesore. In order to kill the bad tree, you have to remove it by its roots. You have to destroy that which feeds it. This is, by far, the more difficult task. Killing the bad tree means digging, cutting, pulling, twisting, sweating, bleeding. It is a job that requires friends. You cannot do it alone.
If you do not remove the bad tree by its roots, it will choke out all of the good trees. They will die from beneath the surface, becoming only hollow trunks, shadows of their former selves. And when the storm comes, the good trees will fall to the ground, and all the dirt will be swept away revealing only the mangled, complex, horrifying, untouched root system of the bad tree.