I don't expect you to be on top of everything but common decency between people who might disagree would help. It's not your fault, usually if you ask a question you get an answer, especially queried to one with a differing opinion. I know sometimes, I form opinions without premise too and I try to be diligent if someone asks me for that.
That's how we learn and is the bedrock of our education system. Just spouting shit off willy nilly will never teach anyone.