I think it is because we live in a "class" society. In England your status is based on your blood line. Here it is based on not only your education level but where you were educated as well as what you do for a living. Did you go to Harvard? Are you a Doctor? Funny that dentist don't get as much respect as a General practitioner ie see old Seinfeld episode
Many cut grass for a little spending money when they were kids and teens so they will always look at grass cutters in that light. That is just the way it is. No matter if you look and act like a Pro. People used to call it Snobbery.