Need to Find the Flaw in My Thinking

Hmmm, so I have long thought that having a PhD in something is not enough to make someone a good college or university teacher and I've long suspected that having a PhD isn't even necessary to being a good college or university teacher.  But, now I'm beginning to think that it's an actual detriment to being a good teacher and is simply a historical accident - the result of scholars needing to have patrons and 'earn' their pay by teaching the patrons' children and then, if monks, to continue the education of the next generation of monks.
I'm setting aside the issue (a fairly large one) of the socialization one gets as one works towards and then achieves a PhD - a socialization that is, I think, rather antithetical to both teaching and taking seriously, really seriously, fields other than one's own.  I'm thinking more of the message that it sends to students - that one needs to be an expert in a field to read about it, have ideas about it or talk about it.  I don't see how it doesn't send this message and given this message, it's no big mystery why students are resistant to speaking in class, offering their own interpretations of material, etc.  I mean, no one goes to a physician for guidance on developing one's own diagnostic and curative skills.  We go to make use of the physician's skills in these areas.  I can understand why, when I need expert advice on something, I'd go to an expert and it seems reasonable that going to an expert I should basically shut up and listen to the expert. 

So, isn't having classes taught by folks who are, ostensibly, experts in their fields communicating the idea that only those who are experts ought to have opinions?  Now, this may be fine if, in fact, we are living in Plato's Republic instead of a democracy, but in a democracy does this make sense?

Someone, please, explain to me the flaw in my thinking because I'm fairly certain that few of my colleagues are going to agree with me on this and I'd prefer to not be viewed as more crazy and out there than I already might be.