This is very true, but it doesn't mean "Use the thing that's worked in the past because that's less risky." Languages get better and tooling improves, and if you're still using one that isn't keeping up then you're increasing risk. These days if your chosen language doesn't have things like strong typing, interfaces, good debugging tools, a good compiler, etc, then you should definitely be asking yourself if it's the right tool for the job.

You shouldn't jump from one language to another every few months, but you should keep a close eye on what other languages are doing and ask yourself if switching would improve the code you write.