One of the major phenomena of Hong Kong in the 1980s and early 1990s was families getting out if they could afford it, because everyone was nervous about the Chinese handover. This wave of emigration even plays a role in contemporary Hong Kong film of the era like Chungking Express. And even before the fears of the handover, many educated HKers were emigrating to the US for the sake of higher wages.

Yes, HKers have ties to HK that are a hassle to break, but plenty of people have broken them and up and left.