It is a great time to learn Rust:
https://www.rust-lang.org/learn
It continues to see adoption in places where C and C++ were the primary choices.
It is exciting to see it in the microcontroller OS space.
If you make a website listing the languages you do understand, people who are concerned can consult it before they begin a project.
> intentionally designed to yield hard to read code
I think if you assume that syntax you find odd/difficult was intended to confound you, I can safely make assumptions of my own.
I understand complaints in other contexts: for instance, if one sends tens of thousands of satellites or burns forests, the mere fact that they are doing it may bother me. But again: what do you care if somebody writes a software project in a language you don't like?
Same for your own project: don't become dependent upon a project that you don't want to have to deal with... If you do, then don't go complain about it: you made the choice to depend upon it.
If I want to modify it, I prefer it to be in a language I understand. The syntax of C/C++ is incomprehensible to me.
See? Anyone can do it. That genre of argument is meritless.