It's not the best way to write analysis code, and it's not the best way to write a web service, but it's probably the best way to write analysis code that runs on a web service.
I picked web services as a random example, not one I'm particularly passionate about. But as a general trend, if you want to combine 2 unrelated domains, Python probably has you covered better or more easily than just about any other language.
You could say the same about a model (or any function) running in R. Want to instantly convert it to a web service? Use plumbr or RestRserve packages for that. Want to make a quick web application around it? Use the shiny package for that.
Just because Python is good at X, doesn't mean other languages are necessarily worse at it.
Comparing python to R, python feels like a much more mature language. R always seemed only useful for small scale projects, e.g. writing some script to process data with < 20 lines of code. Python codebases just scale much better.