A lot of scripting languages are used for rapid development (FR uses a lot of Perl). Much of of the web runs on PHP and JavaScript as well as variants of those.
Still those high-level languages have to be written in something and that something is often C++ or even C. The operating systems themselves are written in some combination of C, C++ and assembly for the hardware-specific code.
Ruby-on-Rails, on the other hand, while easier to get things ready to run (development time in weeks) is not scalable to enterprise level -- it's like the programming language version of MySQl -- useful to a point.