You have things like Rubymotion(to build iOS and Mac apps), which I'm really liking. Opal which translates Ruby to Javascript. You can build Android apps with Ruboto. You can run Ruby the JVM and call Java libraries. You can run Ruby on the .NET runtime(Iron Ruby). You have a really good Web framework called Rails. Most other PHP frameworks just copy Rails, so why not just use the source. You can build games for iOS using Joybox(library for Rubymotion).
So from a business prospective we chose Ruby because we can do pretty much everything in Ruby. We rarely have to use anything else. From command line applications, to web, to iOS, to Android, to reporting, etc.
PHP, well, you can output HTML, or JSON.