To do you the favor of a direct answer: Pretty much, yes.
I don't have a magic brain reader for perfect insight into other folks' motivation, but since you're asking me to guess they mostly use copper for two reasons:
First, because it's expensive and sets them apart from kitchens which can't or won't afford the extra expense -- in other words it makes them look good. Guy Savoy charges more than $400 per cover for their tasting menu. They must exhibit every indication of "no expense spared," possible in order to give their guests a sense of value.
(Have you read economics? Veblen wrote about this, and so did Giffen. Perhaps the "Giffen paradox" where a good is desirable primarly because it's expensive and vice versa, i.e., perceived value is independent of utility, is particularly interesting as it applies to home cooks.)
Second, because copper was the traditional material in good kitchens before the big change in materials. There was a time, not that long ago, when the pans then available did not perform as well as copper. Again, another "feel good" reason where appearance counts for more than any actual performance differences.
Also, you said that the restaurant used "tin-lined" copper. Do you think they use tin instead of stainless for emotional reasons? By your reasoning, we should get tin lined pans instead of stainless because if a Michelin starred restaurant uses tin, it must be better.
Copper is no longer the dominant material in the world's great kitchens. What does it mean to you if two different three stars use Demeyer multi-ply and Sitram stainless respectively?
Let's be adult about it. To the extent that copper might respond a hearbeat quicker to a flame change, and/or might spread the heat an RCH more evenly, in my experience the difference is not enough to make a noticeable different to my (discerning) eye and palate. The lack of difference extends to even the most subtle tasks like browning thin mushrooms or crisping the skin on thin fish. Frankly, if my life depended on the meal I'd just as soon use old Calphalon as copper.
Sorry, but I don't find your evidence, a description of a French postcard with Parisian kitchen porn, convincing. I prefer to rely on my own experience -- which includes plenty of copper, by the way -- and the experience of those whom I know cook at a professional level. But I don't expect my opinion to supercede yours, I'm just giving you the benefit of mine in order to defend Ed's honor.
Furthermore, I would never attempt to dissuade someone from buying copper who can afford it and has already made the decision. There are better things to do than rain on someone else's parade. And, if you believe that copper cookware makes you cook better, you're certainly entitled to your belief. And, more power to you. You seem to think an egg fries better in a Matfer copper/stainless pan than a Vollrath aluminum/stainless multi-ply. You're entitled to your opinion and your egg.