because if one bad teacher ruined your entire education, you're the idiot. likely a vastly emotionally immature one at that.
everyone has bad teachers dude. we also have good ones, and mediocre ones. smart and mature human beings... let it go. miserable stupid ones sit there and stew and are still angry 20 years later about that one embarrass moment... and also blame all their current 'failures' on it. 'oh if only mr handface had not asked me that question in 10th grade English 20 years ago, i'd be a successful music producer!' yeah... right.
but this is peak american entitlement. 'one teacher was mean to me once and i hate school forever and ever' like... i mean that's who the american president is... so yeah peak american. we're a culture of entitled whiny cunts who appreciate nothing an whine about everything and are so egotistical we can't admit that maybe we were a bad student.
ironically... the teachers i liked best were the ones everyone else HATED. why... because they actaully wanted students to learn. The popular teachers people liked were the 'fun' ones who gave everyone As and never actually taught you anything... almost like children want their education to be junk food because it tastes better than broccoli.