A famous environmental campaigner takes a flight, eats meat or drives a car. These are environmentally-damaging activities. They are therefore a hypocrite and can be ignored.
“What is the meaning of life?” This is such a common question that I think most of us take for granted that it is also a valid one.
On seeing this my first reaction, if not outrage, was to think the actions of the teacher were unreasonable. In general I would expect this to be a simple freedom of expression issue.