I’m not saying it’s right to stay in that lane, I’m pointing out that the person speeding doesn’t have any right to be annoyed.
They absolutely do. You are trying to argue that because the person exceeding the speed limit is breaking one law, they have no right to be annoyed at the lane hogger for breaking another law, but ultimately they both have the right to be annoyed at each other. The highway code very clearly says to keep left unless overtaking and no ones attitude to speed will ever be solved by militant lane hoggers who seem to think they are doing the world a service by driving in a way that is more likely to cause an accident than exceeding the speed limit by 10mph ever would.