Actually if you are using C++ on the server there would be an argument for using it in a sandbox like NaCl. After all, you don't want to get pwned on the server any more than the user wants to get pwned by a web game.
C and C++ are already being heavily used on basically all servers.
Linux, the BSDs, the various commercial UNIX systems, OS X, and Windows all make very heavy use of C, and also C++ in some cases.
Apache, nginx, lighttpd, and many other web servers are written in C or C++.
The same goes for the major database systems commonly used today.
The main interpreters for languages like PHP, Python, Perl, and Ruby are written in C. Even if you're using a Java implementation of those languages, or some other language that targets the JVM, the runtime you're using is most likely written using C and C++.
So I find it kind of silly to hear Ruby and PHP advocates say how it's "dangerous" to use C or C++ for server-side development. Their preferred stacks are already essentially all C and C++! The amount of C and C++ code powering their applications dwarfs the amount of Ruby or PHP code they might have written.
True, but the other languages don't necessarily help with that, either. PHP doesn't prevent programmers from writing code susceptible to SQL injection attacks. Ruby doesn't prevent programmers from writing poorly-performing web apps that are brought down or rendered unusable with a even minimal level of traffic. It's dangerous to let those kind of developers write any code.
You can make C safe, it just takes lots of effort, as you see in the software you mentioned. Other languages may require less effort to write safe programmes in.
