Speed isn't the only reason to use C. I often use C not because it's fast, but because C is by far the simplest mainstream programming language. All these UB warts notwithstanding, no language's interface comes as close as C's to a basic, no-frills register machine.
Yeah, we must have different definitions of simplicity, as I expected.
Just off the top of my head, Java has the following complexities that C lacks: exceptions, garbage collection, class inheritance, generics, and a very large standard library.
What definition of simplicity are you using when you say Java is simpler than C?
