The problem is that people ground their egos in their arguments/findings/research etc. If you can resist the prideful urge to do so, your work, and life in general, become much more enjoyable experiences - in my opinion.
If you want to be able to market yourself and access opportunities that other people can't, you often have to project confidence - even overconfidence - in your beliefs. Non-experts can't tell, but they can certainly identify a lack of confidence. People have a bias for simple, clear prognostications, even if they are wrong.
This is an unfortunate reality, but it is a reality. Otherwise, we wouldn't see so many charlatans passing off as experts. But we do.
I think it's useful then to be able to project confidence and even overconfidence in your beliefs. But at the core, you must remain intellectually humble if you want to learn. You can't block out knew ideas because of your ego.
I've summarized this philosophy elsewhere as: look high-status, but be low-status.
I often wonder if the Jewish tradition of casually and constantly debating all manner of things is a good antidote to getting rigidly attached to one's own viewpoint. But on the flipside, nonstop argumentations are a nuisance too.