After all, if you are the one about to go down in flames, wouldn't you be pretty careful about maintenance?
For a privately owned and flown plane, yes, that would be about it, as the balance of freedom and privacy allows a private airplane owner to take a lot of responsibility for the airplane and its operation. However, a "publicly available" commercial plane is held to a higher standard, and it is expected that there will be some second person cross checking (SMS) for safety aspects of the operation.
If the pilot acts as a "director of maintenance", to assure the continued maintenance by an entirely separate organization, who have their own SMS system, that's something. If the pilot is acting as the maintainer within one SMS, that's not nearly as much.