Of course they do. The desire of a person to seek out the facts (knowledge) of a topic hinges on their ability to question their opinions and accept the possibility that they might be incorrect. The people with "strong opinions" will never question simply because they believe their opinions to be unquestionable.

You can't reach these people. The best you can hope for is to offer facts to the fence-sitters, and hopefully garner enough support to relegate the incorrect "strong opinions" to the dustbin of history.

Of course, then comes the delicate situation involving the person with "strong opinions" who happens to be correct. While this sounds good on the surface, these individuals generally don't do their side any favors; when they speak, they sound fanatical and unreasonable, and tend to alienate the fence-sitters. Because they're basically correct, they might be educated on the facts, but I'd be open to ideas how to approach them.

Is that his opinion? Or is that a fact?