I think describing expensive watches/cars/toys/whatever as art is incorrect. I think the best way to think of art as ‘having no purpose, other than itself’ and because of that, watches, while may be very aesthetically pleasing/wonderful bits of engineering/sound investments, are not ‘Art’, because they tell the time/are cars etc.
Its their money, if they choose to put it on their wrist/in their garage/on their wall instead of in an institution, fine. If I had the choice, given the same return I know which is more fun, and what I’d do.
I also wonder if the haters would be quite so passionate in their hatred of these things if a big lottery win came their way. Like all the winners that suddenly and inexplicably start voting for the blue team, post win. Odd, that.