Motivation for using peerid the default IPNS key

Does anyone know what the motivation for using the peerid as the default IPNS key? Is there any particular advantage or use case for the default peerid IPNS key that you can’t do with other generated IPNS keys?

The advantage is that that key must exist already since node initialization, while alternative keys need to be generated and tracked by the user. Other than that, they are the same.