How silly for a non-scientist to express an opinion on a science-related subject.
How silly for a non-driver to express an opinion on a driving-related subject.
How silly for a non-trapeze artist to express an opinion on a trapeze artist-related subject.
How silly for a non-doctor to express an opinion on a medical-related subject.
Well, as the above examples show, the quoted opinion is pretty silly, which is the whole point.
In all of the above examples, people are perfectly free to express an opinion about a subject they have no real knowledge of, but just have to put up with the fact that their un-informed opinion might be silly to anyone who knows what they are talking about.
The democratic fallacy at work again; the screwed-up idea that everyone's opinion is as valuable as anyone elses'. A demonstrably false idea. And somehow, those who foist their ignorance on others with the democratic fallacy always try to make it the informed parties fault that they often don't know enough to have an informed opinion.
Like it's McDonald's fault you scorch your legs with coffee that is (amazingly enough) hot if you drive off from the drive-thru with it clasped between them, or it's McDonald's fault you get fat.