Whenever someone makes a claim to me that someone else is a bad communicator, I first ask them if they understood what the person was trying to communicate. They usually don’t – that’s why they’re making the claim. But if you don’t understand what someone is saying, then you can’t make the claim that they’re a bad communicator!
Consider: I don’t speak French. Voltaire was, by all accounts, a wonderful communicator. But if he spoke to me in French, I wouldn’t understand a word of it. If I then said, “everything that guy said was gibberish, he’s a terrible communicator,” I would be quite the fool.
Sometimes I understand perfectly what someone else is communicating, and I cringe at the way they said it. I see myriad opportunities for misunderstanding or I look around the room and see mostly glazed eyes. Then I can claim bad communication technique on the part of the speaker.
While a communicator is responsible for communicating, that doesn’t mean they’ve failed just because you don’t get it. So don’t immediately write them off as not being worth listening to; it could be that there’s a lot of brilliance just on the other side of a little more fluency on your part.