I do not know why you were told that. I spent the majority of my extracurricular time in college on team obligations and therefore, felt it would be in my best interest to provide an LOR from a coach. I also believe that LOR is one of my strongest so I wouldn't hesistate to provide one if you think it would help your application
The argument is that, in general, they don't know to properly write an academic LOR (structure, content, etc). Not saying I agree or not, but that's the most like reason for hesitation.
If the letter can speak to your leadership/work ethic/or something a coach could knowledgeably comment on, it could be a worthwhile additional LOR.
However, you need to first cover your bases with academic performance from professors/physicians who can legitimately comment on your ability to perform in a medical curriculum. Your coach is not the person to vouch for that.
The argument is that, in general, they don't know to properly write an academic LOR (structure, content, etc). Not saying I agree or not, but that's the most like reason for hesitation.
yep - I agree with this. I would make sure you have all the required LORs from the academic/medical side. The coach is just a bonus character reference
They're always good, and as such don't tell us anything. We know you're all nice people. We need to know if you're smart and the LOR writers would pick you as their doctor (an accolade very few LOR writers actually mention).