That's a slippery slope. When you are staring at a huge stack of accumulated knowledge, you need to decide when you can start ignoring the details past a certain level.
It's not required to know assembly to write code in a modern language, but it helps. It shouldn't be required to know category theory to write code in a modern language either.
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.
Easy to grasp for whom? A first grader? Sixth grader? Twelfth grader? College undergrad? Any specialty or only CS? Or grad level required?
You've forgotten how long it took you to get comfortable with abstract algebra, it's a lot more complex to grasp than you think.