Before Rapture Pro came out, it seemed like there were a lot of 3rd party developers writing patches for Rapture.  You had Pisces and Second Coming from Galbanum, Viral Outbreak from NSL, Biolabs from Biomechanoid, a few from Craig Anderton, the stuff from fiSound, etc.
 
Now it seems there is no 3rd party development for it, outside Digital Sound Factory.  You don't even see any freeware patches for it.  What happened?
 
 

I imagine that the market has been flooded with shiny new toys in the past 10 years.  Probably not much demand left for Rapture sounds, as a market percentage.
 
Nothing wrong with Rapture as far as I am concerned, as I still think it has some of the best sounds available among my soft synth collection.  It's still a fine instrument!  It's just that there are now so many other good, affordable, synths now.
 
Just do a search for the most popular synths and you will see who most of today's sound designers are writing patches for.  Or head on over to the KVR Audio forum and take a look around.  https://www.kvraudio.com/forum/
 
There are a lot of active devs over there...

Rapture (to be truthful never seemed as if it was finished.  I bought the FiSound Universal 120 and the Galbanum Architecture packs.  Because Fisound added the envelopes and many features that should have been attached to Rapture.  Making it more complete.  Galbanum extended the instrument to being like a Kawai K5 with many additive synthesis sounds.  It seems like I can't get the LFo's to turn on and so I am less inclined to use it.  But there has been a lot of love that has been put into that instrument.  I'll try it tonight.