There are a number of things which make one opinion more valuable than another. Holding all other things equal (c.p.), breadth and depth of experience is very, very important. A person's intelligence, acuity, and interest are as well. Even playing ability is part of the equation.
So, c.p., if A has seen two Fazio courses and B has played 20 of them, I would give the nod without a question to B. If I had information regarding the other factors, including whether or not the bloke is a wacko, then I may discount the opinion accordingly. E.g. if Matt Ward tells me that a course is well worth playing, I will make a reasonable effort to see it. If one of the many Fazio and Rees Jones bashers on this site go on and on about another abomination, I'll probably go try to play that one as well. Both opinions are valuable to me, and even though they may lead me toward the same action, they do so for entirely different reasons.
We all want to believe that our experiences and opinions are the most meaningful and valuable. Ultimately, at least with regard to opinions, others get to decide for themselves. Experience is the most important, though many of us won't acknowledge that some of life's best lessons are learned not from books, insight, or inductive reasoning, but from the school of hard knocks.
BTW, Jeff, do you really think that Riviera #10 is a great hole? Very ordinary par 5s, don't you think?