Sibling comment is basically what I meant and my general opinion about the linked website as well.

> You're basically saying that being more knowledgeable about something makes your opinion less useful.

In certain contexts I definitely think this. Imagine you're a CEO that has to decide how to distribute profits among departments. Obviously you'll listen to the head/experts of every department to weigh your options, but you can't really trust them to be unbiased (Obviously not the best analogy but I hope it helps get my point across (: ).