If I had to guess, I’d say that Cathay isn't opposed to model manufacturers making unlicensed models, or concerned about loosing revenue. I think they just don’t like the fact that their intellectual property is being used without consent. They feel disrespected.
And frankly, they shouldn’t be faulted for protecting their brand. From an ethical standpoint, the party exploiting the image of a company without proper consent is the one in the wrong.
Not sure why model brands just don’t go and throw some cash at Cathay out of respect and everyone can be happy.