You are entitled to your opinion, but that does not mean you are right. Your opinion does not matter.
I have a problem with people who are opinionated and are neither an expert on the subject being discussed nor do they have any leverage on the subject or situation. The most common example that comes to my mind is people discussing cricket and football and who they think should be playing in the team or how the shot should have been taken!
This post from Seth Godin sums this up pretty well.
So if your opinion is important and you think it should be heard, what would you do to make it heard?