It's not poachers that cause elephants to evolve not to have tusks.Cause and effect are very complex concepts, probably not even well understood ones, but I would rather avoid descending into the philosophy of cause and effect, so I will just pick a potentially naive idea of cause and effect. Assume a counterfactual world without poachers, would the elephants evolve to be tusk-less? No, so the poachers cause elephants to become tusk-less.
It's that some elephant got a rare mutation, and those mutated elephants aren't as targeted by poachers, thus are able to survive more easily.
That is the mechanism at play under the hood, but it does not mean that the abstraction of poachers causing tusk-less elephants or even more abstractly that evolution causes tusk-less elephants under those circumstances are not also valid descriptions.
Plenty of popsci journos write as if nature is intelligent and driven by some purpose.
Which - to a certain extend - is fine. Countries go to war, wars cause destruction, companies go bankrupt, rivers flow to the ocean, holidays make people happy, programs produce outputs, moving the mouse with the left button down selects text, ... none of this is really true in a certain sense. But that is fine, all our words are abstractions and we understand what they really mean, they do not have to be understood literally and the meaning can be context-dependent.