I think that those are two distinct problems: refusing to take a position (Crono) and refusing to reconsider an entrenched position (Vaniver). I wrote more about the latter, I think I've seen it happening more often to people around me. I especially find it staggering how little effort people spend on picking the opinion to defend vs. how much the expend on defending it.

It's not just about opinions that are worthwhile to have and defend for political reasons and tribe affiliation. My roommate for example will automatically pick the side against me in any argument just to be contrarian, even if it's just between us. Then, he will spend hours performing rationalization and confirmatory research until he has fully convinced himself of a position that he had no prior cause to favor (even I'm the dumbest person in the world, reversing my opinions can't be a truth-signal). Needless to say, after every exercise in this vein he congratulates himself on being extremely intelligent because he "fought well".

I'm not sure if human beings are capable of reasoning about issues without taking positions on them. Without some sort of "bottom line" in our heads, brainstorming becomes very difficult. At least that's the case for me. So I don't think that the advice to avoid taking positions on ideas is helpful. I prefer the opposite approach: take many many many positions on ideas, have multiple sets of beliefs which you use to evaluate ideas with, even if those ideas have conflicts between them, and then weigh all the merits and disadvantages of the beliefs against each other. Committing to all ideas you can think of and committing to none of the ideas you can think of both avoid the problem of getting trapped in a flawed position, but I think the former is easier to do and lends itself better to creative thought and investigation, while the latter makes it difficult to cultivate curiosity.