Just about every organization I am familiar with today is using more languages, frameworks, libraries, etc. than they were a decade ago. Back then, most organizations were doing a lot of Java, and maybe a little bit of PHP or .NET (almost always VB.NET). Now we have Java, Python, Ruby, Go, Swift, etc. And etc., etc.
The problem is that employees don’t come pre-instructed with your selection of languages. Most developers can bring Java or Python and most know at least one other language well. All of them can learn (more on that in a moment), but when hiring, an organization needs to focus on the one or two languages the hiring team is using, not all the languages an organization might ask a developer to learn over the course of their employment. After all, when hiring 20 years ago, the tools of the mainframe team weren’t generally listed as requirements for a desktop developer. While there is a difference (desktop developers were only asked to work on mainframes when the shortage of experienced big iron devs got really bad), it is a similar situation today.
You can hire with an eye to training, and most developers will be more than willing to pick up a new language and learn its ins and outs. But ask any manager that pays close attention, and they’ll let you know that there is a huge difference between time-to-productive and time-to-proficient. One manager told me that any programmer with experience could start contributing relatively quickly in Ruby, but to do the important stuff—things like knowing which array access methods were faster and the most efficient communication between Ruby and other languages—took far longer. His numbers seemed too high, in my opinion and based on my experience, so I asked around. All the managers I know that worked with Ruby (because to a great extent, this is language-dependent, so I didn’t want to make hasty generalizations though, in hindsight, the same data point in Python would have given me more responses) agreed there is a curve, and the range was somewhere between six months to two years. This is strictly anecdotal, but it seems the more technical the team in question, the longer the manager thought proficiency would take.
But even if the lower number is accurate and applies more generally, it is an argument for keeping your language count down. Yes, some languages are better at X or Y or Z than others, but most modern languages can do just about everything an average enterprise team will ask of them. So, keeping languages within a smaller pre-defined set still allows teams to choose the best tool for the job while keeping the number of skills developers at the organization might need down to a manageable level.
And keep wowing them. No matter what languages you are using, your user base is logging in and using the results daily—or perhaps your devices are reporting the results daily or processing them. No matter how you are delivering, you are, as our digital world shows. Keep rocking it, and do what you can to keep the number of languages under your roof down.