Is there a case for sending all used car salesmen straight to jail; do not pass GO?

Should I rephrase that to used car salespersons so I am not accused of being a sexist? Nah, leave the ladies out of this.

My reason for asking such a question is the extremely high frequency the disparaging references to used car salesmen appears in Active Rain Blogs. I am not a car salesman used or otherwise. Never have been and doubt I will ever be. Why on earth would so many real estate practitioners heap so many disparaging remarks on a whole class of people just because of their choice of livelihood.  We real estate agents are often defending ourselves from similar disparaging references by others. We know that there are cases where the criticism may be justified but to use the term real estate agent to universally invoke the idea of devious, cheating, low life opportunist is not true of all real estate agents, hopefully few.  But we seem to have no guilt by dong it to used car salesmen. Why?

 Bill