jp0d, are you non-white? I suspect that many (US) readers may assume that as an immigrant to Australia you are white, having immigrated perhaps from the US or UK, which would make it odd to also name your roommates as such. When in reality most immigrants to Australia are from south- or east-Asian countries (as I'm guessing you may be), making the shorthand "white = natural-born, non-aboriginal Aus citizen" totally natural.
Sorry if I'm off-base… just my guess that this is a miscommunication stemming from the US-centricity of these forums. It's natural after all for a reader to put themself in the shoes of the writer (as did I on first reading of your comment), which can occasionally lead to misunderstandings when race, gender, etc. do not match.