Bo has NO RANGE. He's a straight five note rocker. He's good at what he does, but it's not right for American Idol.
There is some truth to what you say. Bo has a limited range and I have mentioned it in the past.
But he uses it well. I think he has almost as much performance experience as some of the other contestants have been alive.
Bo has the ability to make it APPEAR that he has a wider range. He carefully chooses his songs. This one wasn't wide-ranging, but it had some very diifcult key changes that he took on like an experienced mountain biker on a craggy trail.
And he looks so comfortable on stage. Without being smarmy.
He and Carrie (unless she messes up).
I agree Bo is good but he voice has little range.