"Why do I bother?": well, here's a reason

Why do I bother?.

"All that is necessary for the triumph of evil is that good men do nothing."
[possibly misattributed to Edmund Burke]

Whether Burke said it or not, the thought is still valid.

If we DON'T speak against ignorance and evil ,then ignorance and evil win.

Yeah - it takes a few moments to compose a reasoned reply, and more than likely the author of ignorance will ignore the response.
BUT: if I say NOTHING in response, I am complicit in the evil.