The mistake is looking at C++ as just an enhanced C (understandable given the name, the marketing, etc.). It's kind of like when they marketed Windows as a DOS upgrade...

In reality, C++ is an entirely different language that provides partial C compatibility (in fairness, it is more compatible than just about any other language out there) in order to improve adoption and minimize the impedance mismatch with systems interfaces (which, at least back in the day, were predominantly C, and largely still are).

If we called "C++" "NotC", and then wrapped all the C compatibility features (type coercion, malloc()/free(), C strings, etc.) with a "unsafe mode" flag, it'd all make much more sense.