Your background is good enough. You got RFE maybe because 1): your recommendation letters were not well prepared 2);your petition letter was not well written or organized, 3) or your evidence was not well prepsented.
If you want learn more information about me, please search the posts, rgarding NIW or NIW RFE, written by me with penname "WorthIt".
If you want to dicuss more, email me at yjy_wang@yahoo.com