I think "fob" is just easier to say than "immigrant." Same with ABC.. it's just convenient.
That being said, I doubt anyone has come over on a boat. Now that's just stuff we ship over from Asia (I would know, I used to work in that field. GODDAMN BOATS ALWAYS MAKING MY ORDERS LATE.)
Not sure if "fob" is a bad thing anymore. At least, over here, it's not if used when describing an immigrant-- fob also specifies that it's an Asian immigrant, though I suppose that could be bad?
I don't know. Do y'all think it's not a good word to be using anymore?
I don't know if it's an inherently bad word, but sometimes people can use it as part of an insult, kind of like how there's nothing wrong with the word jew but in the wrong context and delivery you can sound pretty bad.