It's much better that commenting is open, so that people thinking these things can express themselves, and be exposed to different viewpoints, resulting in more thinking and shared knowledge.

Without that, an opinion can fester in someone's mind, becoming worse since there's no way to release it and no visible counterarguments.

In my younger Slashdot days, I would read these polarized discussions, and it taught me about many perspectives on even the simplest thing.