The limits of metaphors
Metaphors are great for explaining things but they aren’t great at being convincing.
When you’re trying to explain something to someone, metaphors work great. That’s because they help transfer an understood frame of reference. It’s like applying a semi-transparent layer from your memory onto the new thing you’re trying to learn about. This overlay lets you build up an insight into how this new thing should be working.
You can start learning the new thing by following and comparing the pencil tracings from your understood layer. This is how metaphors help you bootstrap understanding of any new things you’re learning about.
Persuasion is a different beast altogether. In order to convince somebody of something, you need to help people shift their current outlook. They need to either understand a point from your current mental state. Not strictly though. They can also understand from any other states that provide the same, necessary insight. This insight will allow other people to see your view, spend some time processing it, and sometimes accept it.
Thoughts are complex. They seem easy to us because as ourselves, we have the mental state required to see these thoughts. We already possess the mental state we’d require to be in, in order to correctly process these thoughts. Other people don’t get this state for free. And to get there, other people might need a lot of additional context. Usually a lot more than what you estimate before you start talking and doing any convincing.
Metaphors help us talk about one thing by proxy of another thing. But metaphors are lossy, and some necessary context will always be lost.