Fully agree.
We teachers are humans like everyone else and as such we hold opinions that may or may not be mainstream or PC. But because of the position we hold it is extremely important that we maintain a professional attitude in the classroom and that we are very careful when expressing opinions, if doing that at all.
The classroom is a place for children to receive the best education we can provide them and it is not our personal soapbox from which we should express all our personal opinions about the world.
Present the facts.
Present the curriculum.
And while there is nothing wrong with doing so in an interesting and engaging manner, even with the use of sometimes provocative statements, the purpose is NOT for us to express our opinions.
The purpose is for the pupils to learn and think, and to form their OWN opinions.
Let me give you an actual example from one my my Science classes.
As I entered the class I started by saying:
Youre all a right bunch of apes, arent you?
The class of sixth-graders looked at me as if I had just told them that the sky was falling.
No were not!
I grinned.
Oh, yes you are. Apes, one and all of you.
More protests abounded. Some just sat there shocked that a teacher had just called them an ape.
I waited until the protests had died down.
And now, Im going to show you why.
Thus began our class on Taxonomy.
When we were done the class agreed that not only were they all Apes, but also Eukaryotes, Animals, Vertebrates, Mammals and Primates belonging to the family of Hominidae.
Good times. ^_^