What are you talking about? You could point to hundreds of Minor Leaguers who had great numbers in AA or AAA and didn't do anything in the Pros.
Pea**** or anyone else is no different. Scouts are not deriding his stuff. Guys like Kevin Goldstein just said a few days ago that he has two true plus pitches (fastball, slider). Goldstein says he is a big fan. Others will soon hop on board.
For the record, I'm not knocking on Pea**** - I'm knocking SF's tireless defense of him.