You'd be surprised how many 'bad teachers' I've run across. But it's not just a matter of how good or bad the teacher - no matter what their answer, it's likely to sound like "It just does" to me. My brain is very visual and I just can't visualize abstract formulas & explanations. It takes an exceptional teacher to make me do that. Most don't have the time, even if they have the know-how.
Luckily, higher math isn't a requirement for social survival.
I wouldn't be surprised. Teachers are, more often than not, incompetent. What annoys me is the amount of people that blame mathematics for the teacher's failings.