Is the interop bad?
Well, running "Hello, World" still takes 0.3 ms :D
- Hello world is slow? Really? Yeah, it's not a hello-world-oriented programming language.
- One-based indexing is questionable? Troll much?
- Using `ccall` is unsafe? No kidding, there's no way to call a shared library that doesn't crash if you lie to it.
- `@printf` sucks? Then don't use it. I never do. The `print` function works for 99% of cases.
- Julia development is slowing down? Whiffed on that call.
Regarding the C ffi point, you can use Clang.jl to generate correct bindings so that you don't have to read C header files. But note that if you want to call a function in C you need to look at and match its signature, so it's not all that onerous to have to do the same from Julia. Julia's C interop is so good that several other languages have copied it since it came out.
You definitely should have because from what I saw during my google searches this idiotic article was mentioned a couple of times.
When it comes to work, niche languages lose their ground once you start digging deeper and attempt to venture slightly outside their focus domain. They do not have dedicated teams or industrial money and will always lag behind. Look at DL4J, they have a whole company working on it for many years.
Of course time will tell but considering the results so far I am not convinced that investing time into learning a new language will pay off. Especially considering Julia interop with C/C++.