Why Aristotelian view of physics (impetus and stuff) is wrong?

The Aristotelian view of physics may make sense from the standpoint of everyday human experience, but it lacks explanatory power and doesn't stand up to the test of the scientific method. This means it is inadequate for answering precise questions about theoretical scenarios, which is one of the goals of modern physics. For example, his theory of gravity, that objects move to their "natural place," does not claim to give us the ability to describe how fast an object will move, its trajectory, or any other information except where it will end up; going even farther, it is not even correct about that, as where gravity moves an object to depends on the state of other bodies around it.

Impetus, however, is a completely different idea created by later philosophers (including John Philoponus) to try to rectify some of the issues they saw with Aristotle's theory of motion. Various conceptions of it exist, but the common thread is that it tries to explain the philosopher's perception that projectiles are not affected by gravity the same way falling objects are—a perception that was later shown to be false.