C++ is a mess. It is overly complicated language, so complicated that only few people can say that they know all the bits. And fewer compilers which really complies to C++ standard.
So I think the reason is simplicity and portability.
If you want higher-level and object-oriented programming, then I think C++ is just competed with others like Python. (Note that I programmed in C++ few years, it's fast and has some features from higher-level languages that speeds up development, no offence.)
