No, that is not how argumentation works.
You are just using the statement to press forward your own opinion on an issue that is not being discussed.
It is not a real response on what was actually said before. That makes it invalid. It has nothing to do with agreeing with it or not.
Well, I think that it was being discussed. Hence my response that I disagree.
Anyway, isn't just about everyone pushing forward their opinion? What's the problem with that?