Without looking at old source repos, some of the things I have laying around include:
-- A website classifier: classifies websites against a fixed taxonomy. Roughly as good as AlchemyAPI
-- A English-Language questions answering system. It can answer plain (written) English questions against a knowledge graph. I also have code for a non-Knowledge Based approach (from a Kaggle competition)
-- A somewhat complete Docker based Minecraft server admin tool
I'm sure I could find some other projects kicking around too.
These are all thing I've written as a working programmer in my spare time, while supporting a family. Yes, I'm a white Anglo-Saxon male, and I'm aware that puts me in a somewhat privileged position but I'm not sure the privilege argument makes total sense here.
I do this for fun, not really expecting to see a return. There are plenty of less privileged people who do similar.
Maybe though this is not what one would call a prototype in the context of the article (which might imply a more finished product).
You're in an incredibly privileged position if you can afford to implement tons of prototypes. Many people have an idea but no way to allocate resources towards implementing it because they have less resources to start with, need to care for family, come from an unprivileged background, have less connections and support in the OSS community... This funding offer can act as a springboard and booster for them to join the community and further their development.
Funding those is most likely a worthwhile endeavor. Funding other activities and ongoing maintenance is most likely a worthwhile endeavor as well, but calling a project misguided because it chooses a different focus is wrong and misguided.