Very few can code in C, almost no-one. 30 years experience speaking. If you start out in assembly, then object oriented assembly and learn to write object oriented in C, you have a chance of being meticulous enough to write secure code. You can't take a desktop hacker and turn him into an embedded systems programmer or an encryption software author. The practices used in embedded systems in C to maintain long-term stability and maintainability are not widely known, and even more rare is someone who has those skills and is also comfortable with encryption concepts. The rule "don't write in C" for secure systems is a good rule of thumb. Even the best programmers, ones with 50 and 60 years experience, recommend using something other than C. System legibility and careful abstraction layering, is far more important to security than cleverness and vanity.