Legitimate "ripped" versions (where movies or music are removed to save space) often result in a corrupted gaming experience. Given that Def Jam relies heavily on its soundtrack and entrance videos, a highly compressed version would likely crash during loading screens or lack crucial audio.
The Baddest Brawler on the Go: Revisiting ‘Def Jam: Fight for NY’ (PSP) – Is the “Highly Compressed” Version Worth It? def jam fight for ny psp highly compressed
This leads to the demand for a version.