let me rephrase...it creates a huge sense of pride in one's family members...
remember, they were the one's that listened to you during the whole application process (and empathized) and have kept the faith when most of us have felt like a mugging victim left on the streets. additionally, when they see you walk accross the stage and receive your coat...it provides a sense of relief in that they know, and see, that you are on the road to doing what you have wanted to do for a long while (and ya kinda look like a doctor for the first time).
of course graduation is much more important...no doubt...it's also "more important" then getting accepted in the first place...did you guys and gals not celebrate when you received you first letter (maybe not...perhaps you were signing the mortgage papers for your house😀), but i sure as hell did, and my friends and family were there with me. also, medschool is going to be grueling as hell...anytime for us to celebrate is justified and besides, its provides a reason for partying after the ceremony.
finally, at the UofM, we get our white coats after structure and development (gross, histology, ebryology)...so we actually sorta had to earn it.😉