It’s a warning... My first really good speakers were B&W monitors. Then I had Thiels... Both companies lost their way,
Fortunately, there seem to be some up& coming brands to take their place, even some dedicated to research & measurements-based improvement.
Something similar in sailboats (e.g. Hinckley, Sparkman & Stephens). HInckley is mostly an overpriced motorboat company now, Sparkman is lost.
Marketing and market share is an interesting topic, especially with historical brands. In hi-fi there aren't many long-term examples. A few. McIntosh comes to mind, but Mac is a schizo company. They make more or less traditional gear, and they make over the top goofball stuff. I'm surprised they are able to hold it together, but so far they seem to be capable.
There's ARC, who still sell gear like it's 1970. ARC made an effort in the late '70s to move away from their core product, but quickly saw the writing on the wall, and abandoned that.
JBL made the transition to a more modern 'sound' via research, but at the same time have been able to play on their heritage. And they have a huge multi-national operation behind them. In Asia, the brand may have a bigger 'name appeal' than in the US.
Marantz has a storied name, but a name without any real connection to their origin. In spite of that, my impression is that the Marantz name still holds value.
Denon? Not sure about them. They appear to have been 'dumbed down'--product wise. And how many DL-103s can they sell in order to keep the company afloat (to play off your boat analogy).
Polk has a recognizable name, but IMO doesn't have the historical brand 'love' like B&W. Nothing really negative, but nothing really positive. On the other hand, market-wise, Polk appears to have a pretty good mass-market mail-order gig. Not too expensive, and looking half-way decent in the cosmetic department.
On the other hand, B&W really wants a showroom in order to highlight their 'house' sound, and expert fit 'n finish. Buying a B&W should be like buying an Audi. They exist as a designer, high ticket item. But showrooms are in the twilight of their autumn. So I don't know how it works out for a company like B&W, from a marketing standpoint.
Interesting about boats. I don't know about boats, but in guitar-land you have Fender and Gibson. Or Gibson and Fender. It doesn't seem to matter what they do; those companies will always be top-tier in the marketplace. Even a company as mismanaged as Gibson--its name carries the day for them. And it doesn't seem to have any direct or intrinsic relationship to quality or playability.
FWIW, I recently bought a relatively inexpensive instrument from Schecter. While even non-musicians know Gibson and Fender, unless you are hard-core you've probably never heard of Schecter Guitar Research. But I'll tell you, the SGR was so much better in the playability department than the Fenders I compared it to. The fit and finish was better. And there's plenty of other guitar companies that are the same. But in spite of competition, there will always be Fender and Gibson. Or Gibson and Fender. Can anyone say the same for Denon or B&W?