There seem to be a lot of people who think that arguments about what language to use are 100% fluff and that they can all be neatly settled by the cute "right tool for the job" platitude. The truth is that sometimes we're just not sure what the right tool for the job is and we might do ourselves a favor by being open to different arguments for different tools.
If you're truly committed to "the right tool for the job" be prepared to become a polyglot programmer.
We use 5 (or 6, depending on how you count) different programming languages regularly at my startup and for strong business and technical reasons each of them is "the right tool for the job". We also have some other languages squirreled away in odd corners. In those cases, the languages tend to be "good enough" tools for their jobs (so there's no sensible reason to change something that is already working).
I have a lot of trouble with this statement. It is a tautology, it is necessarily true. Now that we both agree, what is the best tool for the job and how do we choose it? The OP gives the author's perspective. If you don't agree, perhaps you could share yours.