The point is this, even if I'm the fastest coder on earth, write the most elegant software, quickly with very low bug rate, innovate and spread my creativity to

The point is this, even if I'm the fastest coder on earth, write the most elegant software, quickly with very low bug rate, innovate and spread my creativity to the team, if I don't know things like the above, I probably won't be able to work for Google... or will ever be considered a "real" software engineer. Computer Science and Application Development overlap, but are not the same thing, and require at many times, different skills. A great front end developer can understand performance and write efficient code, regardless if he knows all the details of big O notation.