C++, Pascal, Basic, Java, Ada, Oberon all have mature toolchains available from companies that have been in business for the last couple of decades.
As per several C++ retrospective talks, the focus on C is more social issue than anything else.
The social issue may be that many embedded programmers prefer C to C++, for what they believe to be legitimate reasons.
https://astrobe.com/Oberon.htm
C++, Pascal, Basic, Java, Ada, Oberon all have mature toolchains available from companies that have been in business for the last couple of decades.
As per several C++ retrospective talks, the focus on C is more social issue than anything else.