On a Thursday in November of 2009, thousands of students across the University of California system protested against a 32% hike in tuition that had been enacted the same day. Earlier, administrators of the university system were facing a major budget shortfall because the state itself had a major drop in tax revenue, because there had been a major drop in the employment rate, because there was a major drop in consumer spending, because there was a major drop in loans being made, because there was a major drop in confidence between banks as a result of major loan defaults by giant institutions, because of a major loss of equity, because of a major drop in mortgage repayments that the derivative equities were based on. Somewhere in the world a homeowner defaults, and years later a college student feels he's been denied opportunity and justice.
"Shame on you! Shame on you!" the students chanted as one of the university regents members left the building to go home. Shame on who? The regents member for capitulating, or the students for blaming a budget hole on him? The students held a strong opinion, backed with a lot of emotion. But there is a problem with opinions: if you have one, no matter what it is, it's probably wrong. This is statistically speaking, of course: the odds are against you that you came to the right conclusion. Or put another way: of all the opinions that have ever been held by anybody, only a tiny minority turned out to be factually correct. This ranges from the opinion that school buses ought to be painted blue, all the way up to the opinion that the United States should have invaded Iraq.
If you want to avoid being wrong, then opinions are your enemy because their nature--as the conclusion of a single person--means they are unavoidably ill-informed. Even if California didn't have a budget shortfall, for example, there would still be pressure to increase tuition rates due to the Baumol effect and a thousand other legitimate but orthogonal reasons. But is it likely that any given student will be aware of them all when he reacts to the news that he'll have to pay more for the same education next year? Probably not.
If you want to avoid being wrong, you're going to be limited to the kinds of things you chose to be right about: