Everything you have said here is correct but I would like to add one thing. Someone who writes a higher level language (like python, php or ruby) and can under

Everything you have said here is correct but I would like to add one thing. Someone who writes a higher level language (like python, php or ruby) and can understand the internals (written in C not C++) can at times have a distinct advantage. Not only are you able to/capable of understanding what is going on at a deeper level you now have the ability to optimize things in a way that would not normally be possible. On the PHP side I have used C to do some low level optimization that would not have been possible otherwise, and a long time ago simply get some features to work properly.