Chomsky, Authority, and Specialization: A Final Quotation

It would give context if you went back to yesterday's post to read the paragraph preceding the following quotation from Noam Chomsky:

But on the other hand, in discussion or debate concerning social issues or American foreign policy, Vietnam or the Middle East, for example, the issue [of one's credentials to speak on a topic] is constantly raised, often with considerable venom. I've repeatedly been challenged on grounds of credentials, or asked, what special training do you have that entitles you to speak of these matters. The assumption is that people like me, who are outsiders from a professional viewpoint, are not entitled to speak on such things.

Compare mathematics and the political sciences--it's quite striking. In mathematics, in physics, people are concerned with what you say, not with your certification. But in order to speak about social reality, you must have the proper credentials, particularly if you depart from the accepted framework of thinking. Generally speaking, it seems fair to say that the richer the intellectual substance of a field, the less there is a concern for credentials, and the greater is the concern for content. One might even argue that to deal with substantive issues in the ideological disciplines may be a dangerous thing, because these disciplines are not simply concerned with discovering and explaining the facts as they are; rather, they tend to present these facts and interpret them in a manner that conforms to certain ideological requirements, and to become dangerous to established interests if they do not do so.

I see a lot of unproven assertions (which is not a criticism) in the second paragraph especially, but the overriding point still holds that credentials do not inherently determine one's ability or authority to become involved in a discussion. Thoughts?