Notice how the Tweets are sanitized as being merely “controversial”? If he had made the same comments about any other ethnic group, CNN would have called the Tweets “racist” and the professor would not have resigned, he’d have been fired or put on leave.
You see the same thing with media coverage of Antifa and BLM violence. When they attack people or property, rarely if ever are the words "hate" or "extremism" used. They're just good guys who are a little bit too enthusiastic about their righteous cause and who let their emotions get the better of them.