The key point behind being a disgrace is that your having the most fun by not conforming to society's ideals of consumerism and greed.
Note: To be a true disgrace one must not be in or do anything life threatening, instead must be sill and daft at all times.
Person 2 - "because he is the great disgrace"
other examples include
"jimbo you are the great disgrace"
"hes the amount of disgrace"
"hes become the great disgrace"
when you've taken to many drugs - "look at the colours!..oh im such a disgrace"