[toyg]

Multiple-language runtimes typically don’t get popular - people just end up choosing one language and standardizing on it. See for example Windtows Scripting Host: you could always use Javascript with it, but almost nobody ever did in practice. After a while, typically the vendor sees other languages as a drag on development, and they get dropped in favour of the main one.

Retrofitting a multiple-language runtime under VBA would likely be a big endeavour, and in the end most people would probably stick to the established language anyway.