Why the switch from Kharma/Tenor to DarTZeel/VSA

Perhaps, its like that old joke that Woody talks about in the beginning of Annie Hall:

"And it goes like this-I'm paraphrasing: Uh ...
"I would never wanna belong to any club
that would have someone like me for a
member." "

But, why does it seem that some of the original Kharma/Tenor/emm labs club members are switching over to DarTZeel amps and Von Schweikert speakers. On the other hand, it doesn't seem like there are many Tenor hybrids or Kharma speakers going up for sale ... yet