The world moved from C++ to Java on the enterprise side back in the late 1990's. Why? Java was arguably faster and easier to develop in, even though many thought (including me) that C++ was technically a better language.
CppCon 2016: Dan Saks “extern c: Talking to C Programmers about C++”
https://www.youtube.com/watch?v=D7Sd8A6_fYU
Embedded Development with Dan Saks
http://cppcast.com/2016/10/dan-saks/
Regarding Java vs C++, yes the enterprise world has adopted Java, however as someone doing consulting across Java, .NET and C++, I am really seeing it coming back since ANSI C++ has picked up steam again.
I see it in projects related to IoT, AI, VR, big data,....
They are all polyglot projects with C++ plus something else, not C plus something else.
As noted, unless we are speaking about PICs with 8KB and similar, the majority of them can easily be targeted by C++, which is what Arduino and ARM mbed do.
Already in MS-DOS, on 640KB computers, using C made little sense.
When we needed performance, Assembly was the only option, because the code any compiler was generating in those days was average quality on their better days.
When performance wasn't that critical, then the improved type system, RAII, reference types, type safe encapsulations were already better than using plain C.
We even had frameworks like Turbo Vision available.
So if something like a PCW 512 didn't had issues with C++, so a modern micro-controller can also be targeted by it, except for political reasons.
Developers that are against anything other than C, even if their compiler nowadays happens to be written in C++ (e.g. gcc, clang, icc, vc).
In any case, C++ is copy-paste compatible with 99% of C89. So same benefits apply when using that subset.
It is plain language religion as observed at a few C++ conference talks.