I said it on my comment already, OS and console vendors SDKs.
Contrary to common belief among current generation of young developers, C compilers did not always generated good code.
In the 8 and 16 bit days, proper games were done in Assembly. Any language you can think of, were the managed languages of the day.
At the end of the 16bit days, C had widespread enough outside UNIX, that OS vendors started adopting it. So SDKs were then in C.
So many were forced to use C, even if their code was mainly composed of C functions wrapping inline Assembly.
Similarly, around the PS3 time, SDKs started to move to C++. So many didn't had other options than moving along to C++ compilers. But, just like the Assembly generation, many still use mainly C code compiled by a C++ compiler.
So when an OS or console vendor says the language X is the platform's language, they either adopt it, even if only partially, or ignore the platform until they cannot avoid it anymore.
Contrary to common belief among current generation of young developers, C compilers did not always generated good code.
In the 8 and 16 bit days, proper games were done in Assembly. Any language you can think of, were the managed languages of the day.
At the end of the 16bit days, C had widespread enough outside UNIX, that OS vendors started adopting it. So SDKs were then in C.
So many were forced to use C, even if their code was mainly composed of C functions wrapping inline Assembly.
Similarly, around the PS3 time, SDKs started to move to C++. So many didn't had other options than moving along to C++ compilers. But, just like the Assembly generation, many still use mainly C code compiled by a C++ compiler.
So when an OS or console vendor says the language X is the platform's language, they either adopt it, even if only partially, or ignore the platform until they cannot avoid it anymore.