I'm with you on that one; I see zero difference. They can try to justify it all they want, but in the end they are driving a counterfeit cobra. I'm not seeing how we're always made out to be the bad guys.
I have a patient who has spent over £30K renovating a 1957 Speedster that he originally shipped over from The States costing God-knows-how much in parts and labour (I'm guessing the final bill will be £100K+). It's taken him two years and he's still some way from getting it roadworthy.
Clearly it is a labour of love and I respect him for it. But even he says he's fine with people driving £20K replica Speedsters running on Toyota MR2 engines. It's just not for him. No inner hatred. No 'counterfeit' ranting.
For me there isn't a massive distinction between vintage cars and vintage watches. Both the Speedster and Submariner, for instance, are timeless, classic designs. With an original Sub (like a 5513 or 1680) you get the intrinsic value, the history and that warm satisfying feeling you get with a gen. But I defy anyone to wear it as a daily beater, especially a Red 1680 or 1665; just like you wouldn't use a '57 Speedster as a daily commuter wagon.
With a high quality vintage rep you get 'the look', a reliable movement/engine (like the MR2!) and the added bonus of not having to worry about extra dings or scratches. You also get to modify it without worrying about intrinsic value. So the two don't necessarily run contrary to oneanother.
Having said that replication with a view to resale as authentic is just plain wrong and perpetrators should be suitably punished. That's wear the lines get blurred, as much as it must be tempting for people to try...