Both your points are on the money.

I think the author makes a slightly different one. He'd telling his students that for them it is wrong to let themselves off the with "I am entitled to my opinion." So they are not going to be allowed to do that in his class.

He is also telling us, the audience for the article. That he thinks it is wrong when the media turns opposing, unsubstantiated opinions as if they were equally as valid as scientific findings.