Expert communities are grappling with the fact that the internet has, for the first time in recorded history, generally put all recorded knowledge at a person's fingertips. Never mind the fact that many people don't know how to use that tool properly (but think they do...see Dunning-Kruger). Prior to the internet, one of the reasons experts were experts is that they had spent copious amounts of time reading and writing on something that was generally inaccessible to the public. Now that subject matter mostly is, and experts have lost the monopoly on "access," and need to think how they balance the fact that others have the access, but likely not the familiarity and the experience, with a specific subject matter. While many folks may not have the "talent" to use material they've accessed on the internet to actually challenge expertise, I have no doubt that some folks do.
The classic example is the patient in the doctor's office who has done some reading on potential treatment options for his or her condition. Now, without familiarity and experience, they are not likely to understand why the doctor will prescribe treatment X, but at the same time, the Doctor is likely going to have to understand that he or she will have to answer questions of a patient who has access (but not familiarity and experience) to information on health issues. This is a different relationship between expert and the average layperson.
A failure to properly police the profession will also legitimately hurt the perception of experts. Take dentists for example; traditionally,
not as well governed as medicine, and prone to advice/treatments with no basis in science (see - I have access!). My wife has went through an experience with a bad dentist, and now has a suspicion of the profession as a whole. If a profession can't sort its house out, then how can it expect everyone to listen to what it has to say?
Finally, the proliferation of experts can't help either (the article mentions this). Now that universities have become degree-factories, vice houses of a liberal arts education, we are bombarded with folks that claim to be experts because they have a PhD in something banal. Expertise should be (1) challenging to achieve and (2) offer some value to society. I'm not sure all of our experts fit those categories.