Some high school guidance counselors don't care to be familiar with the NCAA academic requirements because they believe that is the job of the HS coach. And some coaches assume it is the guidance counselor's responsibility, and as PABaseballDad mentioned, then the athletes are caught in the middle and end up not being eligible.
I sometimes get the impression through some of our junior college clients that the JUCO counselors are worse. We just had a football client be ruled not eligible as a 4-2-4 transfer back to D1 because he was misadvised by the JUCO on the requirements for his Associates Degree THREE times. Not only is he not eligible, but his family paid for courses that he was advised to take which are of no use to him.