Yeah, I acknowledge this problem. I think the attitude to be taken is intellectual humility. A digression: the 17th century Spanish mystic Miguel de Molinos wrote, in his Spiritual Guide that Disentangles the Soul a couple chapters on humility that, I think, are the best and most profound on the topic anywhere. What he said is that humility does not consist in acting humble. You're not going to fool God, he says, by lowering your head and refusing to accept compliments. Humility is just the right relation to something.
I have two masters degrees and a PhD from elite universities. I am a lifelong student and I am paid to study and write and teach. I am struck daily by how little I know, and how dumb are the very smartest of us, me included. However, I also know when something I read or hear is just wrong or poorly argued. I don't think that's merely a matter of judgement. The theologian Bernard Lonergan wrote his masterwork Insight on this topic. It's worth reading.
Taking that idea, I have little respect for someone who takes a position from laziness, or just because they want to take it because it aleiviates their guilt. That's a lack of humility. But someone who has studied deeply and arrived even at a conclusion with which I disagree, I respect. It's fairly easy to tell the difference. In practical terms, it's difficult to know for sure-it's a problem I'm working on. I'll write a book on it when I'm finished, if I live that long. However-here's the critical point-I see the need for justification as a moral imperative, and so it cannot be ignored merely because we lack a practical solution.
To re-acknowledge your point in another way, then, we are also not absolved from any moral violations we commit in mistaken service to this ideal. So if we shut someone up who had justification we wrongly judged to be bad justification, saying we thought we were doing the right thing does not excuse our wrong action. It's a thorny problem.