Except the teams that consistently out perform recruiting like Boise State etc. This graph actually tells us that it is a combination of talent and coaching. You can do more with less and less with more depending on how good of a coach you have. In other words there are clearly two variables in this equation (which is the opposite of your point) and yes on the whole if one variable has a higher value the results (sum) will have a higher value. That doesn't mean that the other variable isn't important or equally important. For a team like ISU that is never going to be much higher than midlevel talent that is the one variable we can control to get above mid level results. Right now it is clear we have average coaching and average recruiting and so we have average results.
I would say it shows that the vast, vast majority of the time its all about talent, given that the vast majority of schools fall in there somewhere. Coaching can affect that to a small degree, but talent is clearly the overriding factor here.