I just came across this discussion and feel great sympathy for the original poster.
I’ve had only one unpleasant yoga experience (not at a hot yoga or Bikram studio). It certainly was upsetting; it was like a violation of trust.
At the Bikram studio I’ve attended for three years, every one of the teachers radiates loving-kindness. They are very gentle, very attentive and somehow manage to give personal attention in class and still keep that all-important timing. Amazing. Good, good teachers are out there.