KRS-One is the latest hip hop legend to emerge as a HipHop50 celebration defector, and his reasons are crystal clear -- the Grammys aren't worthy of his presence!!! The T'Cha was noticeably absent from the latest 50-year celebration that highlighted old and new stars such as Will Smith, 2 Chainz,…

Something awesome happened to TMZ on a random street corner in Hollywood last night ... and no, it didn't involve crack or hookers ... but rather hip hop legend KRS-One. The rap pioneer was coolin' off outside of AV club, where he had just performed a set ... when he decided to bless the TMZ…