The problem, though, is the context. The article I linked presented the assorted category theory tools as things the community 'really should be using'.
And doing that has an effect, in that it increases the number of concepts that a person needs to grok to be a functioning member of the community -- to be able to dive into open-source code, discuss code with other participants, etc. Adding concepts should only happen when it's clear that the benefits are larger than the costs -- not just for the individual, but for the community. It requires far less knowledge to dive into a Ruby or JS codebase than it does a Scala codebase. And adding "category theory" as a necessary prereq for being part of the Scala community just makes things incredibly exclusive.
What would you suggest? Banning everyone who likes functional programming off the internet, so they do not post thing about things that you do not like? To be fair, I have seen very few projects that use scalaz or cats.
The thing is, the basics of abstract algebra are easy to grasp, and you don't need to spend a lifetime studying; it takes a couple hours to get started with these simple (but powerful) concepts.
Why would someone in elementary or middle school need to learn that though? I think anyone in high school could easily learn a bit of abstract algebra.
And doing that has an effect, in that it increases the number of concepts that a person needs to grok to be a functioning member of the community -- to be able to dive into open-source code, discuss code with other participants, etc. Adding concepts should only happen when it's clear that the benefits are larger than the costs -- not just for the individual, but for the community. It requires far less knowledge to dive into a Ruby or JS codebase than it does a Scala codebase. And adding "category theory" as a necessary prereq for being part of the Scala community just makes things incredibly exclusive.