A valid concern from the student's perspective, too. But its relative - many well above average HS students would fall into the "below average student" category at these and other top academic schools! And even those that don't sometimes will feel that way at times! You won't have time for SB if its a constant struggle to keep up academically. While the SB coach may have scholarship money or have some leeway with admissions, YOU should also be working w/ the admissions people to make sure of the academic fit. Just another reason to choose your school carefully without making SB the primary consideration! In other words, from a career perspective, you want to be able to say I graduated from Stanford and played softball rather than I played softball during the one year I was at Stanford!
One thing that really impressed me at the schools where we have done unofficial visits are the academic resources provided to student athletes. I am sure it is designed to help the football and basketball players, but if a student athlete takes advantage of all of the academic resources available to them they have a much better chance of graduating than a regular student!!!