For example, some like to point out that that only teachers are unionized, among the professions. Alas, this is just wrong. Unionization depends far more on your industry and/or employer than whether you are a member of a profession. Many lawyers and doctors who work in the public sector are unionized, example. More importantly, one should acknowledge that nurses and airline pilots are generally members of unions. So, the next time you hear that unions are incompatible with high quality professionals, just respond "Airline Pilots."
Of course, it is not just teacher bashers who make poor comparison to other professions. Have you ever hear teachers complain that they are not being treated like professionals? For example, strictures on what or how they teach are not befitting their professional status. What they seem to miss is that they work for someone else. Young attorneys are closely supervised and their work is checked. Clients can dictate strategy and tactics, even overriding their attorney's professional judgement. Doctors have layer upon layer of oversight, both during their residency periods and later (e.g. insurance companies who second guess their treatment plans).
I am all for comparisons to other professions. I think that we can learn a lot by looking at parallel situations, because it is often quite difficult to get a good perspective on our own. We can learn from the experiences of others, both stealing the good and trying to avoid the bad.
The problem, however, is when these comparisons are based on fantasies. Some of them are literally based on fantasies, such as when people's knowledge of how law firms work are based upon what they've seen on television. Others are a bit more personal. But all of them could be addressed simply by talking to people to ask them about their work. All of them could be addressed by doing some research or some reading.
Instead, however, too many people love the facile and uninformed comparison.
Being more thoughtful means interrogating your own thinking and your own examples, comparisons and analogies. It means trying to verify your claims with people who are in a position to know, and looking to see if there already exists clear overwhelming counter-arguments. We want to encourage our students to do this, no? Whether it is a mathematical argument, a historical argument, a literary argument or a scientific argument, we want them to be more thoughtful than that.
So, why can't the adults who argue about to improve education do the same?