Freedom of speech isn't a one way street. If you take other people's money you're obliged to watch your mouth.
OK, for a professor, a supposedly educated man, his choice of words in the essay was simply 'dumb'. It was a very poor judgment call on his behalf to word his point the way he did. If he would have explained his point as he did in the interview article, this would not be a discussion topic. I definitely do not agree with him.
However, what you have said above about tax dollars is completely ludicrous. "obliged to watch your mouth"? That's like saying, "You work for Ford Motor Company. Ford pays your salary. Don't ever bad mouth Ford. And God forbid you ever drive a Chevy. You are 'obliged' to back Ford." The same thing happened recently when a beer company employee was caught in a newspaper ad drinking a rival beer and was fired. This country gives you the freedom of choice. This country gives you the right to speak freely. Choose your words carefully.
There are many things I don't like my tax dollars going toward, but people still are entitled to their own opinion, as you are entitled to yours. What makes his opinion any more right/wrong than yours? Nothing. Because it is simply that, an opinion. So, feel free to agree/disagree with it, but don't claim that he is 'obliged' to do anything. Free opinions have no restrictions, only consequences.
I've chosen my words very carefully, and the First Amendment gives all of us the right to speak our mind. But, you're saying that it's a one way street, with no responsibility taken for what one says.
I'm saying that I don't want to pay Churchill's salary with my tax dollars. That's my opinion, it's my right to say that, and it's my right to tell politicians that I strongly disagree with where my tax dollars are going.
Free opinions have no restrictions, ...
Of course they do. Wherever you got the idea that a man can say what he wants, anyplace, and any time, is fantasy - not reality. Common sense usually tells people that they don't tick off the people who pay their salaries. In other words "they watch their mouths" around the people who sign their checks. This is common practice in private business, and it's no different in the public sector.
If Churchill was in private practice I'd have to problem with what he said no matter how much I dislike it. However, once a man puts his hand out for federal funds he's obligated, by common decency, to show respect for where those funds came from. If he doesn't I have every right to ask that his taxpayer's funding be stopped.