I think stuff like this all depends on the situation and the vet.
The first vet I saw that took care of Raider, actually listened and talked with me, and was understanding of me being wary of certain medications (taking info from here and experianced members who warn to stay away from certain medications because of appetite loss and all). I was so sad that she moved shortly after I had seen her. That office referred me to someone else, he was very rough, and asked me if my chinchilla had been vomiting.(as far as I know, chinchillas can't vomit...) And then there's a local emergency vet who sees exotics (he checked out my friend's chinchilla when he was acting weird, hypoglycemia I think was what it was, it was a while back) but he was very knowledgeable.
As other people have said, it's important for there to be open communication between vet and owner. No one likes being talked at or being treated like they know nothing. Especially when there are owners who do their best to learn about their animals and how best to care for them. I'm sure there are pet owners who come in, and really don't know much, but there are people, like many on this forum, who know a great deal. I've found that this forum is an invaluable resource. It enables people to be able to treat minor issues at home, and know what to do when bigger issues come up.
as others have said, there's a time and a place for both types of knowledge, and it all really depends on the case and the vet.