Just like the toe curl and ankle point from my previous post, being a teacher and being good at a trade are two totally different skill sets.
As a teacher, communication is key. It's more important than even proper technique, because how can you teach something you can't communicate? As a teacher you should be prepared to say the same thing fifteen different ways and still not have someone understand you. You should value imagery and metaphors and comparisons in order to get pictures into your students’ brains. You should be check-listing every single action you take while in the air so you can communicate everything that is happening.
I often see teachers only explain the moving parts of a combo, while so much activation is happening elsewhere and may not be readily visible (especially for untrained eyes). For example, when teaching a Skin the Cat (STC)* a poor teacher may only focus on the core and legs being picked up and forget to communicate what the arms are doing. They may explain lifting the knees into the chest, scooping the pelvis, keeping the legs as tucked as possible as they slide between the arms, and then extend straight as the hips pass the elbows. Unfortunately, about half of the move has been ignored. The students will not know to engage their shoulders, pull down on their apparatus, actively press the arms towards the legs as they raise up, or begin to open their chest as the legs continue to dip down.
A teacher explaining this way is more likely to injure their students as they focus solely on the core and legs and abandon their shoulders. Students learning like this will struggle to master the move or end up compensating to learn an energy-expensive version. Teachers must have body awareness throughout the entire move and the entire body and then be able to effectively communicate how others can recreate this.
There's a pole teacher at The Vertitude who astounds me because she is not super strong and cannot perform crazy-hard moves, but she understands teaching so well she can teach moves she's never done before. She can walk just about anyone through a move with no demo while they're still in the apparatus, even those who are visual learners. She can see where angles are supposed to be and successfully explain that to a group of students. I love taking her classes because I always learn more than just pole from her.
It takes a lot of time and energy to be able to see what she sees. Take as many classes as your can. Look for the tiny differences in what the teachers does versus what your peers are doing. Find what is different between those succeeding and those struggling. Look at the shapes their bodies are making, what is open versus what is closed, the angles both between body part to body part and between body part to apparatus, the differences in speed and momentum, and anything else you can possibly see. If you see something you don't understand, ask. If the teacher isn't sure, check online. Youtube has a ton of fitness how-tos and may give you an answer.
As far as improving communication techniques, I recommend you start by reading books - ANY books, just go read! Reading books helps flourish our imagination while allowing us to practice grammar and language. When you're taking classes, listen to imagery used by other teachers. Practice communicating these small details while training in the air or at home in front of a mirror. You could even take a speech class at a local college (I seriously recommend this if you are able). If you're already teaching, ask your students where they're getting stuck, then when repeating your demonstration actively assess every part of your body to find what you haven't explained yet. When you find it, try to find colorful imagery that could help hook the thought in your student's brains, even if it's weird. To me, the weirder the better. At times I say things that makes the entire class laugh uncomfortably, yet they all understand exactly what I meant and improved because of it.
So, do those who can't do, teach? Sometimes. But, it doesn't matter how talented you are. If your words cannot reach your students, you cannot teach. Thus, I think those who can't teach, do.
*For those who don’t know, this is a skin the cat: https://youtu.be/g0Bcj-Qv75s