Why so many B & W Speakers on the used market?

Showroom sound that gets annoying after staying with it a while combined with the volume sold, that will lead to a lot of used gear.

They wow on first listen but end up being a nagging bright, overly bitey sounding with hollow midrange presentation when you stay with it. The same thing that made them excite on first listen is what makes them unfit for staying with in your home.

Other will say something else but that is the underlying reason @cooperdude6 

The only other tangible reason is purchase addiction as is the norm in this space of buying stuff to play music with but end up obsessing over the stuff than the music lol

They pair well with Macintosh electronics which many people like the looks of.

High end buyers tend to be older.  Older people tend to die, or downsize their living spaces.  Surviving spouses may not have shared their deceased husband’s hobby.  Generalizing, but in my area of Eastern Massachusetts we see a lot of this.

Probably the main reason is because there are so many B&W models out there.  Same reason why you’ll see more Ford F150’s for sale than any given  Lamborghini.

I think there's 2 reasons for amount of used B&W's on the market:

1. They have been around for 60 years and have always had a pretty broad range of speaker choices, across many price points. They have also developed a wide range of retailers and distributors.

2. I also agree with some posts here that B&W's seem very forward and can be fatiguing, to my ears, especially at the lower end of their range.

When partnered with more laid back sounding electronics they can be a nice listen.