There are too many heads. Even if only a minority breaks the general rule, this minority will still be numerous enough to be uncontrollable and to cause, sooner or later, irreparable damage. Society, like all large and composite entities, is a perfect illustration of the law of chaos. As populations increase along with their necessities, more and more of nature is destroyed and human expectations of what nature is shrink more and more. In spite of videos and much documentation about nature in its true grandeur, for the viewer it is becoming more and more like a dream, like a report about some alien planet.
Unscrupulous profit is within immediate reach while the threat of doom still seems far away.
Let's not forget natural competition. He is profiting from my worries so why should I suffer. And here is how the trees in my own neighbourhood disappeared. Even a tenant who may stay a few weeks or months or maybe a year cuts all the trees he can in the courtyard for some futile reason or without even knowing why. Those trees, of course, don't belong to him, but to a landlord who doesn't give a damn.