The good part of this: don't fall into the trap of believing the proposition "an idiot disagrees with me, so I must be right". That's solid advice, idiots believe countless true things and geniuses believe innumerable false things. The intelligence of a random interlocutor has nothing to do with the validity of their opinions, really, so it shouldn't serve as evidence one way or another. Generally, I try to pay attention to good arguments against my ideas, not good arguers.
I think the advice for who to listen to is very bad, though. He calls it being "slightly elitist", but his bar is beneath the ground. The example for discussing politics is knowing what the three branches of government are - I knew that when I was 8 and I don't think I had anything interesting to say about politics back then. I definitely couldn't have given a meaningful critique on the latest policy debate, and neither can anyone possessing merely the most basic knowledge of rudimentary facts on the topic.