That’s true. He was an honorable man and took that fork in the road. He could have had any position he wanted in the Union Army.
Lee probably would have win the war in three years (and perhaps in two) and we might never have heard of Grant. Albert Sidney Johnston and Stonewall Jackson wound have given Lee trouble, But Lee would have been more decisive than MacClellan. He would have understood the vast resources at his command and taken great risks sooner that other Union generals refused to do until 1863 or ‘64. He would have suffered a lost battle if it meant taking Richmond.
...But that is why Lee fought for the Confederacy. He couldn’t imagine doing that to his native state.