Most users don't see security, they see speed and latency.
Example for gaming: why are most games in C++?
C++ provides fastest speed/latency from the hardware without low-level effort.
In all areas where real-time control is critical, speed/latency are most important.
Imagine a Java GC stopping a program for a few milliseconds to recover memory, while it controls a fighter jet.
A server that is 30% slower because its written in Ada.
A program that requires 50% more memory, exceeding physical RAM and starting to swap.
Even C sometimes not fit to the task of extracting maximum performance, especially on embedded/mobile devices. Assembler(which is far less secure than C) is still used for speed-critical loops, audio/video decoders, cryptography and compression.
Users can sometimes see security failures (e. g. ransomware, data loss) as well as performance failures.
If it's only about speed you could argue games could have been written in C, I think C++ is used because it give the best trade-off between performance and productivity/software maintenance.
Imagine that people perfectly lived with lower computing resources few years ago and a small amount of performance gains could be traded in favor for security leading to a world with less security nightmares.
I think Javas misplacement in safety-critical or real-time-critical environments is not primarily because of its low performance, but because of its non-determinism. The most important thing in real-time applications is not primarily performance but rather timeliness.
Safety-critical or mission critical environments (aviation, military) often prefer Ada or its safer subset SPARK over error-prone languages such as C.
In all areas where real-time control is critical, speed/latency are most important.
Imagine a Java GC stopping a program for a few milliseconds to recover memory, while it controls a fighter jet. A server that is 30% slower because its written in Ada. A program that requires 50% more memory, exceeding physical RAM and starting to swap.
Even C sometimes not fit to the task of extracting maximum performance, especially on embedded/mobile devices. Assembler(which is far less secure than C) is still used for speed-critical loops, audio/video decoders, cryptography and compression.