I hope you will agree that there are things where C is not the optimal choice (e.g. you wouldn't choose C for writing scripts). Many people argue that C is still suitable if you need maximal performance or do stuff that is very close to the hardware, like operating systems. Now, people who say that C shouldn't be used at all are just convinced that even in those applications there are now better choices than C. Safer languages like Rust exist that at least claim to fill the same niche as C.