Commentators emphasize that David's disqualification was not a punishment for sin. His wars were largely righteous, defending God's people. However, God designated that His temple, a house of peace, should be built by a man of peace (Solomon), not a warrior. This shows that a person can be righteous and called by God for one task (like warfare) but unsuited for another (like building a sanctuary). It's about fitness for the role, not a judgment on David's character.