People who are worth less than a "
Piece Of Trash" or / and "Piece Of Shit"
Depending on the context: A Piece Of Trash can be lower than
a Piece Of Shit since "Shit" can be used for useful purposes such as Furtalizer.
But a Piece Of Shit can be lower than a Piece Of Trash.
In any of the above context, a "Piece Of Garbage" is less or lower than the the above.
Therefore if a person is a "Piece Of Garbage" their worth is the lowest on the 'Worthless Scale'.