Most fakes are pretty easy to spot, others are more difficult... if you handle any of them you can immediately tell which are genuine, and which are not; if you can examine any of them, ideally with a loop, the fit and finish on even the "highest quality fake" watches are dramatically subpar, the problem is being able to tell the difference on a swinging wrist. In this instance, there are unique traits, that vary by watch brand, which can show fake/genuine, but if its a brand I am not interested in, likely I would not be looking for these traits.
I am a bit at a loss as to the rational for wearing a fake watch, I have spotted some fakes even on local nsx owner's wrists, but its something you don't want to call them on, as it could cause great embarrassment. I am personally interested in swiss watches for the craftsmanship, and the attention to detail that goes into production, none of which would be present in a "grade aaa chinese fake with knock off automatic movement", so what would be the point? If you're wearing it in heritage to the brand, its a knock off, and has no such lineage; if you're wearing it as a status symbol, its a fake, and you're a poseur. The only possible explanation would perhaps be to determine if its a model you would be comfortable with, and you're interested in trying it out. In this situation, you could easily go to an AR and try the watch out, to determine if its something you like.
The nice thing about authentic watches, especially in an economy which seems to be in decline, is they're assets that don't lose value, and may increase in value. I recently sold one of my breitlings to a person in France, and received more than I had paid for the watch when it was new, four years later. This is in large part a result of the declining dollar, but even in domestic sales fine watches lose very little, if any, value over time. If you use a watch as a daily wear it will take some abuse, and value will decrease, but even then, this decrease in value is less than the cost of a fake watch, and a fake watch is worthless in regards to ownership, service, and resale (which is illegal). It makes no sense, even from the standpoint of cost, to purchase a fake watch.
