Actually, that joke is a bit misleading because med school graduates must apply for residencies. The one that finishes first usually gets his top choice of places and field of study. The person that finishes last doesn’t, and often even fails to match. The top of the med school class generally does neurosurgery, ObGyn, Dermatology, Plastic Surgery, Orthopedic surgery, anesthesiology, radiology, and some other type of surgery. The bottom of the class generally does pediatrics, family medicine, psychiatry and a few others (some top graduates do these because they truly choose to). The point I am trying to make is that GPAs DO make a difference when graduating from medical school. Yes, they are all called doctor but they cannot all do the same thing. Med school is only half of the training, and in some fields it isn’t even halfway (neurosurgery is another 7-9 years after med school).
Wow…had no idea that my pediatrician and GP suck… LOL
As I said, some choose it but some have no choice. Just like in theatre. Some choose community or regional for the lifestyle/location and some just never make it on Broadway even though they would love to and would prefer to be there. I have a cousin that is doing pediatrics and never really wanted to, but could not match in the preferred dermatology. Doesn’t mean she sucks (she graduated from HS as salutatorian of a 500 student school, had a 4.0 in biochemical engineering, but med school grades weren’t in the top half of the class). She’s still a great doctor, just not doing what she would like. Sometimes we get to choose our path, and sometimes we make the best of what is handed to us.
You are over-analyzing a joke @Dusing2 
In theatre, a lot more weight is placed on talent for undergrad and grad admissions. I guess if the want to portray Dr Horrible from Dr Horrible’s Sing Along Blog, they might need a good med school GPA, but if the flunked out and became disillusioned they could play Sweeney Todd:-)