It may depend on one's line of work. If you have to keep track of billable hours, it could come in handy. That's what I have used mine for in the past. However, some of my friends create the need to use it, say time how long a frozen pizza is in the toaster oven, or time how long they have been sitting in traffic, or maybe the most useful thing is timing how long you have until a parking meter runs out. However, in general, most of my friends that have chronographs never use them.
dn't be so quick to make assumptions about people based on their watch. people like us who study, talk about and are obsessed about watches are a very small minority of the watch population. I don't think too many watch companies would stay in business if we were the entire customer base. Most high end watches are bought by people who just like the way they look and/or want a status symbol. I know some people who have some very serious watches and know very little about them just that they are expensive status symbols.
It is very possible that this guy walked into a shop and decided to pick up the Hublot because it caught his eye or because the salesman might have told him that is what's popular now or any other reason. If it had been a different time or different watch shop, he might have walked out with a Royal Oak or a Nautilus bought for the same reason(s) and you wouldn't be thinking douche.
In general I agree with your post. However, there are stereotypes for lots of brands (be it clothing, watches, cars etc). Sometimes, it can be difficult to understand why someone would buy a brand we dislike or view as overpriced. Personally, for the price of some of the limited edition Hublot's I often wonder why someone doesn't purchase a different brand...but to each his own. In the end, there are owners who behave in a manner that dispel stereotypes and there are those that behave in a manner that perpetuate the stereotype. I'd like to think, we are all able to give someone an opportunity to show us the type of person they are regardless of their purchase choices.