Well, Richard Mille is sort-of in a class by himself. I visited their Boston boutique a couple of years ago, and was surprised they actually let me handle a watch. Maybe that was the company I was with--an audio company boss and a former general counsel for a major corporation you have heard of.
I do agree that Mille has always been his own thing. Guy's whole brand marches to the beat of its own drum. To be fair to Mille though, I do own a few of his watches. They always feel great on the wrist because they're all extremely light. I just wouldn't recommend them to most people on account of price and the aesthetic. Most won't admit why they buy these (but I will). A Mille is bought first for prestige and the extreme recognisability. Kudos to Mille for focusing all his efforts into making excellent headway to mainstream pop culture though.
Also, I don't think Mille would sell half his watches if his boutiques weren't the opposite of the old guard. It's mostly because you have to "feel the Mille," and that's when the watches tend to really blow someone away. Of course, the type of people likely to be "blown away" are the type who consider a 6-7 figure impulse buy a non-problem (I should hope so).
The elegant sport-watch category is still alive, but not at the center of focus of the watch biz. But these are pricey--the AP RO, the Girard-Perregaux Laureato, the Vacheron-Constantin Overseas (my personal favorite of this style), even the Hublot Fusion (not the Big Bang). The Zenith Defy 21 fits in that category. One of the chief exemplars of this style back when it was dominant was the Ebel Sport Classic, the chronograph version of which was presented earlier in this thread by both myself and Frank Dernie (whose example is much cooler than mine because of how he got it). Countering the elegance of these examples was the Rolex Datejust, which never claimed "elegance"--and the "diver-esque" tendency is a good observation.
Some companies still focus on elegant sport watches, at not such elevated price points. Movado (via their premium Concord and Ebel brands) offers the Concord Mariner and Ebel Sport Classic, of which I am today wearing a newish all-titanium limited edition with an incredibly light bead-blasted wave bracelet. Stylish, without being minimalist or "fancy". Both of those companies also produced big, showy watches in the ROO tradition (which actually came after the Hublot Big Bang, which as much as any started that trendlet), and I have several Concord C1's and an Ebel Tekton. Everyone needs a few 48mm watches.
But most people equate sport watches with tool watches. I like me some divers, to be sure, but a diver is a tool watch more than a sport watch.
Rick "'sport' in the sense of...spectating" Denney
I'm honestly surprised to see someone say the category is just "alive." The way I've experienced it, and interpret what you're saying is that the normally out-of-reach designs have started trickling down into the more affordable segments after god knows how many decades of remaining an impossibility for so many watch lovers. It's never been bigger, imo. If I look at it another way though, I can see where you might be coming from...that same trickle-down could dilute the mystique behind this exclusive category; thereby, making it less relevant over the long run.
I must contend the point about the conflation of the tool watch and the sports watch. I think that confusion stems more from the fact that these sports watches share a few traits with the king of highly desirable tool watches...Rolex. Those traits would be [lack of] accessibility, mystique, marketing, and show-offability. Most sports watches tend to be associated with water-based activities (though leisure yachting is usually the implied activity) not unlike the Submariner so there might also be some confusion there. I personally just think it has more to do with the fact that they all happen to be exclusive watches that are not readily available for purchase.
Vacheron-Constantin Overseas (my personal favorite of this style)
I LOVE the Overseas even though I'm pretty torn between which iteration I like more. The 2nd phase ones with the guilloche/engine-turned triangles in the dial have a lot of personality. Whereas, the 3rd phase ones with the reflective enamel dials simply exude elegance. My overseas is in another property, and since I've only just started taking pictures of my collection this month I have no photos to post until I allow myself to start business travelling again.
Sadly, I only have the Patek Philippe Nautilus on-hand at the moment. Some might say it's the most overrated of the bunch, and I'm inclined to agree. It is, however, one of my favourites. Upon closer examination, extremely subtle mirror-finished anglage/chamfering is present in nearly every part of the case and bracelet. It is not merely a technical exercise to show you what Patek is capable of. The overall effect makes the Nautilus shinier than it has any right to be even though it mostly features a brushed finish. However, most people who see it at a distance won't understand what makes it so strangely "radiant." I've seen homages that lack those "curves" it is absolutely not the same overall effect. The same can be said for the aquanaut's dial. Those milled lines on the dial have tiny-tiny chamfers that create a surprisingly outsized 3d effect. Without it, as with blatant homages, the dial looks flat and lifeless.
I've definitely gone and talked up a storm so I should probably stop here.