I mean, that can be answered in any of the 7000 Rosen threads already on board.
Take the work ethic and leadership question marks out of the equation. He has actually had former teammates speak up on that.
The concussion issue...well look at it like this. How many concussions has he had? How about Darnold? Mayfield? How many have they all had dating back to high school? What happens if we draft Mayfield and he gets his eggs scrambled in 2 consecutive games?
Point being unless you have access to his medical records you don't really know the whole story. You know what the media and other posters feed you.
Lastly he is a potential franchise changing QB. If you are ok with him at 12 the is absolutely zero legitimate reason not to slide up and take him at 2.