sure if you have the time but I already spend a lot of time making myself smarter in a variety of realms and I don't necessarily have spare time for the particular item of conversation. Your right though that in general that communication and collaboration regardless of level really helps everyone understand things better.
It would also be waste of time if the "dumb" person is arguing in bad-faith. I would even argue that it's smart to value your time and redirect it to something worthwhile, as you've said.