The only real problem I see is completely unrelated to any of the
implicated technologies; it's the staff question. Developers learn
python because companies use python. Companies use python because
developers know python.
Companies will use Python for a reason. Perhaps those reasons will just be historical, maybe the first application was written in Python when it was less corporate but now you have >10,000 lines of Python to maintain. So you employ more Python programmers to maintain and expand your applications. Substitute the any language for Python in the above and the argument remains. If you are starting something new and there is some existing library that would give you a big head start then you might pick a new language. But it will not make much sense to do so just for the hell of it given that you will be have a massive learning curve for the new field and then adding an additional learning curve for a new language
In fact it has nothing to do with the language and more to do with the tools available in the field. Lua's field of expertise is being embeddable and as a scripting language within a less flexible frameworks / languages. This has lead it to become a lean language which can be exploited for that outside it's traditional fields. But unless that is absolutely what you need then using Lua does not make sense
I didn't convert one of our core applications to Lua just for a laugh but because it improved the application many fold (cost / benefit). However there is little benefit to using Lua for our other applications. We have our workflow nailed down just so, we have considerable experience in the tools we use. We cannot throw that away without good reason
So we will continue to employ Ruby programmers just as others will continue to employ Python, Java and even PHP programmers
