This article illustrates why not. The author is a professional engineer, but he can't depend on the body that licenses him--the government of Minnesota--to judge him by objective professional standards as he advocates for better engineering practices, because it's a government and therefore a fundamentally political organization, not a professional one.
Do you think that politics can somehow only exist in government? I disagree, politics play significant part in any human endeavors, see for example office politics, corporate politics, etc.
The problem here is that this gentleman is speaking truth to power, and power doesn't like that very much. The professional organization being governmental, or having a government-granted monopoly, versus being a private organization, is basically irrelevant. The organization being part of the government usually grants additional public oversight, not less.