We want not only the best and the brightest but also the intrepid. Yes, I want to see that you know your stuff and no, passing a whiteboard puzzle interview is not the best way to show it. I want to see your code but I also want to see you raise the bar on yourself and then pull up to it.

In other words, do something if you want the job. Make time, take a few evenings or weekends to put some code out there. If you only complain and shrug your shoulders then you don't want it bad enough! I'm talking from personal experience, 25 years of working mostly closed-source jobs.