Rating restaurants (and hotels) is a notoriously difficult business. No matter what you do, there will be some very valid criticisms. It is therefore truly remarkable how consistent and deservedly well-respected Michelin guides in Europe are. While nobody could agree with every rating, there is really nothing better, and hasn't been for a very long time.
Unfortunately, the quality of the Guides decrease the further from Paris you go. The American ones are still quite usable, but are not as good as the competition. The Guides in Asia are hardly worth opening.
The reviewers in Hong Kong and Macau were clearly not the best European reviewers period, but they were also still European, and so had difficulty reviewing any kind of Chinese cuisine. At the end of the day, Michelin simply ranked the places with established names high, and less famous ones low. Tastes may differ, but it is impossible to imagine that there exists a single person in the food-eating world that would give three stars to Robuchon in Macau while giving less to the ones in New York and Paris. And I don't think there is a single person who lived in Hong Kong for more than a year that would place Lung King Heen (a decent but very white-tourist-oriented restaurant in Four Seasons) as the top Cantonese restaurant in the city.
This said, the guide follows famous touristy places rather well. If you are visiting Hong Kong for the first time, and have nowhere to turn for advice, this guide is probably better than nothing. You might end up spending more money, and eating much less well than you could, but at least you won't be completely lost. Which is the only reason I give this guide two stars rather than one.