A shotgun blast, or even a well-aimed rifle bullet, has greater range and is much more devastating to continued operation of the drone than a stick.
The chimpanzee was putting up the best defense he had at his disposal. First, recognizing this intruder as a threat, then acting upon that threat. This seems to be a lesson that many have already forgotten in this world.
The chimp seems to be smarter than the drone pilot, what was that fool thinking?
Using the stick showed quick thinking on the part of the chimp. The chimp quickly realized that the usual response of flinging poop was not going to be up to the task and so escalated the armed response.
Well played Zippy.