I think the actual reason it has not taken off is because of the ecosystem. You can translate Python, but nobody using a high-level language like Python uses just Python. The first time you pull in a library and are met with a wall of English documentation, error codes, and APIs, you're right back to where you started. Low-level OS APIs are also in English. I suspect there is a lot of potential being left on the table here, but it's a massive undertaking because you need to translate not only a language but also enough of an ecosystem for people to be able to make programs.