That's an excellent question.  Why would scientists in other professions urge scientific standards in fields other than their own?

It's simple.  Scientists do specialize, but the scientific method is applied to all branches of science.  Urging people to apply scientific methods to all branches of science is part of the overall objective of the scientific community.  

Similarly, if I were a journalist specializing in one beat, I'd nevertheless want to urge all would-be journalists to employ ethical standards of journalism in any other beat.

There may be some disciplines where the public has a strong interest in the subject, and a lot of ink appears on the subject, including some doubtful ink.  Scientists or journalists in unrelated fields would naturally feel the need to urge appropriate tools of science or journalism, so as to avoid the kind of mistakes that have plagued human civilizations since the dawn of recorded history.

Urging people to examine the evidence for (or against) some theory with a skeptical eye is simply sound advice, regardless of the subject.  The dissent is not against any theory.  The dissent is against sloppy methods for establishing which theories are viable, and how we can be so sure of what we claim to believe.