Can't this already be handled by calling out to a C/C++ or FORTRAN procedure that processes the data in multiple threads? For number crunching, Python is almost exclusively used as glue.
You CAN handle it, but why should you have to? If it's possible to remove that barrier, then it absolutely should be removed. If the only answer to a problem is "use another language", then the language in question has a limitation that needs to be addressed.
It is not a limitation at all in this case. Python is just a front to Tensorflow and similar libraries/frameworks so GIL doesn't matter there.
Today's machine learning and data science students don't know how to code in those languages. They know python, and maybe java.
Don't forget R...
shudders
What's wrong with R? I know it's not a programmers language but it's great for getting things done.