By this logic no C or C++ developer in history is a professional programmer. Approximately zero non-trivial programs have been written in C or C++ without memory management problems and/or vulnerabilities.

That's an ignorant and wrong assertion, spoken with an incredible amount of confidence.

Look up software verification. There are verifiers for C.

This is misleading. Formally verifying the behaviour of any large software is a really tall task, no matter what language they are written in.

That's not what the parent comment asserted though.

Often it's the employer encouraging the programmers to cut corners.

With a lot of things I agree with this statement, but not about memory management in C.

It's the "fault" of the programmer, but the language makes it very easy to make these faults, so I'd say it's the fault of the language.

No, it’s the market.