There are two reasons.
1) specific, very uncommon situations. Such as clergy and another situation I can think of is notary income or state grants for certain industry specific projects, which are taxable for federal. But, that's why I say, people nearly always know that they are in a 'different' situation that requires adjustment. There isn't actually any reason that normal self-employment income would be adjusted, so I wouldn't worry that you are missing out on anything - I know this line may make you feel that way! - it's deceiving.
2) The most common reason this line might be used, is if you are a part-year resident and are filing in multiple states, with some income not earned in the state, or as a non-resident reporting income earned in the state. As a resident all earnings are reported.
