That one word was all that was needed in that case. It was not infantile except to you. Some posts can be replied to with just one word where appropriate. That post was just such a case buddy.
No, the post offers absolutely nothing, what state would the forum be in if every time someone posted something we didn’t agree with we all simply wrote rubbish, more rubbish etc. Maybe expand on why you disagree and not simply right rubbish.