I had to scroll back and re-read my own post several times to find out where the confusion lies. I was talking about people who don't have an opinion on something and just shutting down other people trying to discuss it. Saying "Boring" isn't an opinion on the subject- its an interjection on the conversation itself. To further illustrate this :
Person A: I think mass effect is scientifically accurate.
Person B : I disagree. Here's why....
Person C : Boring! *rolls eyes*
^ A and B have an opinion. C would have no opinion of the subject. He interjecting with his indifference. That's not an opinion.
I am not sure I should stick my fingers in this one, but C does in fact state an opinion: he/she just doesn't consider the topic important enough to explicate said opinion further. The comment is - however much you (as A, B, or an extrernal observer) disagree with both the form and content of the statement - relevant to the ongoing discussion: A and B want to throw themselves into a debate on the scientific merits of mass effect, C considers this a waste of time, and expresses his thought in what he/she considers the most expedite form: to actually launch him/herself into a debate as to why he/she holds such an opinion would actually weaken the very point C is trying to make. While this can come off as trolling, A and B now in fact have the perfectly acceptable strategy of ignoring C, and keep their discussion going; whenever C wanders off in search of a snack (within 5 seconds from the last statement, we can presume
), A and B no longer have to wonder what is going on.
I do understand your frustration with people who use this strategy, repeatedly and exclusively; but it is not annoying because it is a lack of opinion, it is annoying because it violates our accepted rules for conversation: saying it once makes the point, saying it over and over violates a number of principles of cooperation; even then, I would be careful about making statements about a person's intelligence, as said principles can and are often flouted on purpose and for valid reasons.