Do people think that or are you mixing up ideas that are not directly related?
Are people evil? I suppose that is a matter of perspective. Most people are not but we are all capable of wrong-doing. You might consider something to be perfectly OK - using make up, being a passenger in car, heating your home, keeping a pet - but someone else might consider it evil to do things that contribute to environmental harm. You might think it is OK to eat a burger but someone else might think it evil to kill animals for food. There are some things we probably all agree is wrong - murder, robbery, violence, child abuse. Otherwise, it is all a matter of perspective. In general, people are not evil. The world is inanimate and so incapable of being evil.
Humans will be extinct one day unless they can evolve faster than the changes to their environment. That is unlikely, though evolution is a continuous process so we are already changing very slowly. They can delay that crunch-point by artificially protecting themselves from environmental changes or by decreasing the rate of environmental change. Humans will not be extinct soon though it is almost inevitable that they will be one day. That is the fate of most animals, with or without human intervention. It is not something I hope for or expect to see.
The extinction of species does not depend on how 'good' or 'evil' they were.