My $0.02: there's a gradient between listening charitably (e.g., assuming that your interlocutor probably meant something sensible, and therefore that the senseless thing you heard doesn't accurately reflect their meaning) on the one hand, prioritizing your time (e.g., disengaging from discussions that seem like a waste of time, either with silence or with cached politeness or whatever) on the other, and refusing to challenge error (e.g., pretending something is reasonable because pointing out the flaws with it feels rude) on a third.

Only the third of those seems like a problem to me.

Where you draw the threshold of too-much-in-that-third-bucket is a really up to you. You're under no ethical obligation to prompt non-cached thoughts from everyone who talks to you.