I think they mean gulf style as seen by westerners. You can get a visa but you'll never be seen as a "local" nor granted citizenship. In places like Dubai multiple generations live without ever getting citizenship or a path to it and always with the notion you can be booted at any minute if you inconvenient the wrong person or run out of money.

Though I don't think this is fully true of Japan -- it's one of the easiest countries to naturalize in if you give up your other citizenships but does have the quality of always being seen as a foreigner. It's just that few people naturalize as Japanese because their immigration is most open to people from developed countries who aren't interested in giving up their birth passport to acquire Japanese nationality. If you just want a Japanese passport though no matter the downsides, I think it's one of the easier citizenship to get for an American to obtain.