If it's anything like the moans I've heard from teachers, they didn't like him because he advocated them doing that odd thing called teaching and kids actually having to do exams all in one go rather than a series of bits or doing umpteen bits of work to get qualifications which meant they might have to teach and pass information. Bizarre concept in this era of something for nothing. Something else they didn't seem to like was having to be fully aware of who is in their lesson and control a class and not send the disruptive ones to be someone else's problem.
I am of the class of 79 and 81, when we did proper exams.
I remember one of my old teachers moaning about how crap GCSEs were and how he wanted to go back to real exams.
It will be interesting to see the grades in a few weeks as I believe kids this year sat proper exams.