Those caring about performance are already using Python, in combination with extension modules written in C/Cython. You would have to complete your argument by explaining why they would rather switch to a completely new language without a huge (scientific) ecosystem of libraries, instead of writing more extension modules in the places where it really matters.
The appeal of a scripting language is that "automatation and little applications" do not take a lot of friction to write, I'd say OCaml is less suited in this regard.
I don't follow. I am not talking about any kind of cause. However, you made a specific prediction, that "Python will be beaten", and I'm saying you haven't made a proper argument why that is so.
As someone who cares about performance I still use Python for the non-performance critical parts of code, which is the vast majority.
I'm pretty sure that in the end this is just a matter of personal preference, but you make it sound as if there are objective arguments without actually presenting them.
My line of thought while replying to the parent is that if a rewrite is needed, those that are more performance minded, are likely to use a language that doesn't suffer from GIL or a pure interpreter as canonical implementation.
Somehow you can already see it on the interwebs. The majority of Go and Julia users come from Python and Ruby, not from languages that have AOT/JIT compilers on their toolchains.[0]
This is just my gut feeling from almost 30 years watching similar technology transitions.
I have no data to back it up and may be completly wrong.
[0] There is PyPy, but I never saw it being deployed in production systems.
The appeal of a scripting language is that "automatation and little applications" do not take a lot of friction to write, I'd say OCaml is less suited in this regard.