Why so many JL Audio Fathom subs for sale I wonder

Just mulling some thoughts around about JL Audio subwoofers. Been thinking of adding one, maybe 2 to my system. They are awesome subs and come highly reviewed in the Absolute Sound, and Stereophile. Recommended components, powerful as hell, accurate, flexible...all very positive attributes. I have a few friends that own F112's, F113's.
So why do so many of them show up for sale here on A-gon? I'de like to get some input from A-gon members as to why that might be? Seems baffling that something so highly regarded and affordable ends up for sale so often. Thoughts anyone?