Yeah, but you were still in a teaching position.
You probably did a bad job because you're not skilled in teaching. That's what I meant by saying you're a bad teacher.
I could've said you're "bad at teaching" and that may have made things clearer for you, my mistake.
They could've been exceptionally inept, and even if they were, I'm still going to stick with my initial conclusion that you're bad at teaching.
It's okay, most people are and you don't have to be ashamed of it. Everyone won't be on your side when you say it's someone else's fault that they couldn't learn from you effectively.