I can second what Terry says, I have been to the school he runs several times and been very well received both as a passer by (just paying my landing fees) and as a paying customer for an aerobatic lesson. Instructors were first rate, as was the welcome every time.
Most of the schools I have been to have been relatively pleasant, there have been a few which were more geared towards the "pilot farm" which I generally find less friendly rather than the warm club atmosphere that I look for. We are allowed to be different and seek different places.
That's it - students are customers, they pay their hard earned cash for the lessons, and nobody should EVER be treated like that - it is their career, surely they should at the very least act professional! It is just damn right rude! It's not his fault that he didn't receive the training that they themselves deem best...!
That kind of behaviour - in this day and age is a very very thin line. I know a few that would have taken to social media and destroyed their online reputation for much less!