That's because VistaPro is under at least semi-active development on the PC. Back in... '04? ish? or thereabouts I asked the developer if he'd consider rejoining the Amiga market with future versions and he said he'd definitely be interested if the userbase was there.
So, at least on the vistapro front... y' never know.
I'd love a new VistaPro for AOS4. Even though VP has been greatly outclassed by scenery generating 3D programs on the other platforms, it can still be a lot of fun. I purchased the old VistaPro and the MakePath addon program for the 68K Amiga back in the day, and I still fire them up from time to time.