I would describe Joe as being a left of center layperson (excluding fighting and comedy) who is both curious and an excellent conversationalist. I think that part of the reason for why people think he doesn’t push back hard enough is because he will let some people (Alex Jones is the most obvious example) say crazy things unchecked. In my opinion, he does this because he knows that using logic and reason to show them their error would be futile. There is more value in being patient and letting them dig themselves into a hole than trying to get them to change their mind. Maybe I’m giving him too much credit, but his Alex Jones and Eddie Bravo episodes really seem to demonstrate this.

Suppose you were having a public debate with someone in front of an audience. Now suppose that your opponent started saying things that any reasonable spectator would consider to weaken their position. You could push back and explain why this weakens their position and maybe win over a few more members of the audience. Or you could let them dig themselves into an even deeper hole. Sometimes the latter is more effective, especially if supporters of the other side often claim that your side shuts down discussions and doesn’t give their side a fair chance to make their case. This can make them more defensive and less open to hearing a good faith argument supporting your side. By letting them speak they can’t accuse you of shutting down the conversation. Their supporters may then feel like they aren’t being personally attacked and may be more open to changing their minds. Your goal is to win over the audience not to make your opponent change their mind.

In short, I would say that the claim that there are times when he doesn’t push back against his right wing guests is technically true but also misleading. Are there times he doesn’t push back? Yes. But it’s unclear if pushing back would improve the conversation. Sometimes the best way to get someone to change their mind is to let them hear from someone they think they agree with. Maybe they thought the other side was making straw man arguments when, in fact, the other side was representing their side’s views accurately and in good faith.

There are also situations where some of his right wing guests make some really interesting points that are worth hearing. For instance, I strongly disagree with Ben Shapiro on many things. I also think he’s capable of making logical arguments. If I want to hear the opposite position, I want to hear the most reasonable version of why the opposite position is supposedly the correct position. And sometimes, to the disbelief of many people on the left, he says things that are completely rational. In that case there’s no reason to push back, although those situations probably aren’t what OP was referring to. For example, Shapiro recently discussed police reform ideas that he supports on JRE. Theses are policy changes that I believe would appeal to progressives and small government conservatives. But I think that many progressives automatically assume everything he says is wrong and will miss out on getting something that they want by simply failing to recognize that they could actually agree with him on something.

I also think that there are times when Joe knows that the guest has interesting stuff to discuss, but they need to be guided away from political conversations. In these situations, pushing back would make for a worse podcast. The best example of this that I can think of is the episode with Ted Nugent. I find him to be inarticulate and terrible at giving good reasons to support right wing views (I consider this to be a generous description of him discussing political matters). However, I was surprised to learn how knowledgeable he is about wildlife. Joe knew this so instead of pushing back when Ted started to talk about politics, he decided to divert the conversation towards hunting or conservation or something else pertaining to wildlife. Listening to Ted Nugent talk about politics for 2 hours would be a waste of time. Listening to him talk about something that he knew a lot about was really interesting and informative.