Doctors? They self-regulate the size of labor supply in their fields, inflating their salaries. Why do you think we have a doctor shortage? You really think there aren't enough smart people to do the job? No, the AMA controls the number of med school graduates each year by limiting the number of accredited medical schools. They also lobby governments to legislate that nurses can't perform medical procedures (all towards the not-so-discrete goal of preserving their six-figure salaries).
Teachers? They can't be fired thanks to tenure policies. This was the biggest issue with public schooling when I grew up, and [continues to be](http://www.nytimes.com/2010/04/16/nyregion/16rubber.html?_r=...). Survive three years and you have job security for life. If my workplace hired and fired based on seniority, we would have gone bankrupt years ago.
Firefighters and policemen also can do no wrong--aside from amazing pensions they have great job security and the power to help those they know more than others in the event of disaster (e.g. Katrina).
For every example of those in the "heroic professions" doing the right thing, you have the same careerism and self-preservation that those in private industry strive for. But in many people's eyes, they can do no wrong.