Well, at my day job, not having to throw out 10 years worth of legacy code would be considered "a bit of a plus". We also have 1,200 employees and precisely two engineers who have ever done a Rails application more complicated than the 15-minute-blog demo. I think we have one guy who coded a Python app once.
Our favorite contractors and outsourcing providers also have (comparatively speaking) deep skills in Java and the related stacks. Some of them have forgotten more than I ever want to know about, e.g., serializing Java beans.
If you pick as JVM language as suggested, why would you need to throw out any code?
When I worked at ITA Software which writes much of their stuff in Lisp (not the web stuff though), there was often worry that it meant new programmers would have to learn the language and so wouldn't be productive at first. But learning the code base takes a lot longer than learning the language, at least enough of the language to get significant stuff done.
If you have 10 years worth of legacy code written by 12,000 employees, I assume you're in the same boat.
Our favorite contractors and outsourcing providers also have (comparatively speaking) deep skills in Java and the related stacks. Some of them have forgotten more than I ever want to know about, e.g., serializing Java beans.