Hi Paul,
As far as I know FilterMeister initially was created out of interest for Filter Factory and not particularly for creating commercial quality plugins.
Usually volunteer work start out of interest and joy: if it goes well it might get clear that some income could be created with it.
Filter Factory was a (first?) plugin created for creating Adobe Photoshop compatible plugins.
Enthusiastic about the concept, eventually disappointed by its limitations and convinced it could be done much better Alex Hunter went for it and created FilterMeister.
When it grew it gained interest, bugs were fixed and later even feature requests were added. At a certain point FM got good enough to ask money for it. Especially when Alex got volunteer co-developers.
The more FM matured the more it got clear to some power users it could be used to create commercial-quality filters. The intentions were there but destiny decided otherwise: Alex got health issues and had to cut back on development input.
Co-developers did it as volunteer work in their spare time so spending time on FM was not their main priority. Slower development rate on top of more feature requests regarding moving-on technology the development of FM could not keep up. When it got too much behind frustration kicked in and co-developers started to go their own way. In the end co-developer Harald Heim in a way was the main developer: he used FM to create his own commercial filters but while doing so he improved FM for his own use to get additional development functionality and every now and then he made time to create a new FM version with features added he initially created for his own work. This way FM still got more useful with each release. At some point Alex was able to release a version which supported 64-bit: one of the big feature requests. Yet, new big feature requests started piling up and the nagging about this and complaints about outdated docs by new users resulted in more frustration and everybody giving up on FM and going their own way.
Along the way Alex was asked to deal with his inability to keep up with FM development like hiring programmers, selling FM or releasing source code but he postponed that for a long time, after all, FM was his baby he wanted to pick up again some day when he would have more time and be more fit again. Eventually giving up on that hope the source code was released but only when too much damage was caused by lack of FM development for too long.
Commercially FilterMeister is not viable anymore these days: even with some dedicated minds updating it to todays standards it likely won't be received with open arms by the general public anymore due to changes of interests.
Still, just like you do, I can imagine a dedicated soul who sees the potential of this basically all-round relatively simple to code tool to create or manipulate images for aesthetic or technical purposes could find joy in using the -as far as I know now available for free- FM sourcecode as a basis for a more up-to-date version. I am convinced there are geeks out there who would appreciate it and helped with it big time...but not the ordinary guy anymore. FM is a tool; a versatile tool.
Roberto