I have strong opinions on certain topics, but unlike some people I know, I try to justify my opinions (see, for example, my philosophy page). Whether I succeed or not is another matter, but I think that the attempt at justification deserves at least some credit. And I've been known to change my mind if I'm convinced I'm wrong.
I take a somewhat dim view of the idea that all opinions matter, or that no one is ever wrong. I know at least one or two people who seem offended whenever anyone tried to point out flaws in their ideas. I think this goes beyond not being able to handle criticism; they are of the belief that every opinion has a bit of right in it. I know other people who consider it the height of rudeness to try and convince another person to change his or her beliefs. There's a tendency today to treat opinions like an outgrowth of your body, like a limb, and to equate the desire to change it with the desire to cut off one's hand. With this sort of attitude, one does not debate so much as exchange ideas.
I never understood this stance. Yes, the exchange of ideas is important, but what's the point of having an opinion if you don't believe said opinion is the correct one - or, at least, on the right track? I mean, why else would you have it in the first place? Because you like the colour? And if you believe that your opinion is at least partially correct, why on earth would you not try to convince other people?
Note that I said convince, not bludgeon into submission. Obviously, one should not force one's opinions on anyone else. By force I mean physically force - your opinion ends where another person's nose begins. And note also that an attempt at persuasion does not count as physical force.
This is why I have absolutely no problem with, say, Baptist Christians passing out flyers saying that non-believers will suffer eternal hellfire, or Jehovah's Witnesses coming to my door to explain why they think blood transfusions are evil. These people have a right to their opinions and a right to evangelize. I, in turn, have the right to consider their beliefs utterly ludicrous, and to tell them so - bluntly - if I want. If the conversation turns physical, then there would be a problem, but there would be a problem with anyone getting coercive in this manner, regardless of the context.
At the end of the day, it is up to the individual to decide for him or herself what the truth is. This is not the same as saying that every opinion has merit, or that there's no such thing as universal truth or falsehood. It's nothing more than a statement of jurisdiction and jealous sovereignty over one's own soul.