1) Continuity; the first thing he said was that he wasn't going to sing and dance for the little jimmys anymore. It's the polar opposite of what he used to be, which is he wants... his music was a big part of his old gimmick and the lack of music is a big part of his new gimmick.
2) It's memorable & unique; R-truth already stands out from the modern superstar by being the first in a long time without an entrance theme who isn't a jobber, sure some didn't have themes in the 80s and early 90s but I did say MODERN, it'll also stand out to the first time viewer, by all accounts R-Truth will probably be the first wrestler a first time viewer will remember due to lack of music.
3) It's an incredibly heely thing to do which is good considering R-Truth is a heel
4) It puts the focus on R-Truth in his entrance, he talks to himself as he enters the ring and it adds emphasize to the fact he's unstable without any promo time, again good for the new viewer and also can progress the story within the confines of an entrance.
