Rails, instead, uses an high level language (Ruby) and creates a homogeneous, well designed and complete environment for web application development.
These are my first impressions: maybe I am wrong.
This post is written for another religion war: Python vs Ruby. I belive it's a war without sense and I think it's usefull learning both.
Will learn more than a language will help me? yes! Because...
...you must use the more confortable tool......for a specific task. C and C++ are usefull for real-time applications and for videogames. They're not very good to write CGI or web applications. Java is good on servers, but I think isn't good for heavyweight audio manipulations.
I found myself comfortable with Python in many cases, but it is very likely I will use Ruby more often. Remember: the silver bullet is an anti-pattern. Learning more languages will give you more instruments to work better and faster. In programming there's not a Holy Grail, just the right tool in the right place.