Some of the comments below are talking about how to successfully argue against the move. Does your company have some history you can point out? We've had enough of these type guys and their failed space ship projects that any proposal for a language shift, or major framework adoption is viewed with skepticism first.

We've dealt with "new guy wants to overhaul ..." scenario. When I joined this company we were a C++ shop with some Perl and bash. Multiple new recruits successfully lobbied to implement refactors, or new projects in a hot language/framework. Several of the refactors were a huge waste of resources that either didn't come to fruition, or were only partially successful.

Now, we are a Perl shop with active development in 3 other languages(not counting front end), and we're maintaining legacy apps in an additional 4 languages. And we've deprecated apps in at least 3 additional languages.

I guess I should be thankful none of them have lobbied for switching databases. :-O On any given year, we average 3-4 programmers and 2-4 contractors(mostly front end) Two of us have been there 15+ years, but the other full timers seem to move on around the three year mark. Because of that all the hot shots have left. When a major bug is discovered in their code it can take a long time to fix, and any breakage due to upgrades is quite a hassle since those of us left aren't experts at every language we have to maintain.