It's probably important to separate the IP aspect from the trade war in general, not only because IP enforcement was almost assuredly an after-the-fact justification that played a negligible role in the decision process to set the global market back almost 100 years, but because IP enforcement and infringement is a nuanced and complex topic that merits a conversation in its own right.
All things being equal, behind a veil of ignorance, yes, people probably shouldn't steal the ideas of others and profit off of their work. But this is more important in the context of true intellectual property (patents) in the areas of technology, programming and medicine as opposed to softer IP (trademarks) in terms of manufacturing and product design. Theft of IP and process for beneficial items that require a huge sunk cost to develop, such as medicine or computer programs creates a very real risk of chilling development. Why invest all of this money and effort into creating a useful drug or product if someone can just come along and sell that product as if it was theirs? It offends our sense of fairness if a lone game developer, who spent three years toiling away to create his magnum opus, can't make any money off of it because someone else copies the code and sells it for proceeds with impunity. There are counterarguments to be sure, i.e., the free flow of ideas to benefit a greater number of people than otherwise, but the free-rider problem is significant.
Reps, on the other hand, exist in this weird little zone of reality in that they don't compete much if at all with the established brand. Someone that pirates a $10 movie might very well have paid that to see that movie; most people who buy a $200 replica wouldn't have bought the $10,000 gen. And further, owning the rep might even make it more likely that the owner purchases a gen down the line--it isn't an alternative so much as it is a separate product. This is all shooting from the hip, but I think that the existence of good reps offends Rolex's sense of exclusivity and eltism rather than their bottom line.
Would be interested to hear other people's thoughts.