Well untrained programmers who have no business writing C apps in the first place, for starters.
Everyone here is completely glossing over this as if it were suggested that this is intended for everybody, for every solution. If you're not extremely confident in your C skills, or have the experience to back it up, This is NOT for you! If you think you can only do it with another language, then This is NOT for you! If you think you're gonna write the next Amazon, This is NOT for you!
And lets not forgot just how many things are written in C and still running the internet. It's just another tool in your toolbox.
Linus Torvalds is "extremely confident in his C skills". Doesn't stop hundreds of CVEs per year targeted at the kernel.
Sick of the C Apologism Task Force's idea that "if only rockstar programmers wrote code we wouldn't have any problems", completely ignoring the reality of software development and the evidence of 50 years of exploits.
50 years of the same bugs over and over - the language might let you shoot yourself, but that doesn't abdicate the programmer from continuing education, code review, or testing. Seacord has a whole book on avoiding these; arguably anyone without it isn't doing all they can to write safe code, and might as well be considered uneducated. You can write unsafe code in any language if you don't know what's going on, or not a 'rockstar'
As for Linus, the kernel was written when he was a student, and I doubt he personally still makes the same low hanging fruit vulnerabilities that are the big issue.
Everybody makes mistakes, no matter how confident they are in C. And while there are numerous things written in C, there is also a continuous stream of bugs and vulnerabilities as well.
That’s not to say that other languages are perfect, but there are much safer options that are still very fast, such as Rust, or even C# or Java.