I was in a startup where that first rule was violated. One of the other founders wasn't listening to me. It drove me insane pretty quickly so I left.
Sorry to hear it. We had some of that at first as well, which is why we all sat down and basically came up with that one. Luckily, it turns out we work pretty well together, so over time we got good at listening and arguing without marginalizing. At first though, it was really hard.