This termimology was invented by white guys who are stygmatized by others for having a relationship with an asian woman. The perception that women of Asian origin are pushovers is an absolute ludicrous thought and racist and anyone who has married one can attest to that. JAWGWAC's can use the expression with each other as a term of endearment as protection from the snickering of others. The "Chick" portion is tongue and cheek and is playing off the stereotype.
"Im sitting in a restuarant with 5 other JAWGWAC's, I feel like a cliche"
JAWGWAAC is a negative sterotype