Programming is not the same as understanding algorithms and data structures.
If that statistic is true, I would say that they probably understand algorithms very well, can prove the runtimes, know which data structures to use and why, etc. What they can't do is actually implement it in working code, or write anything else outside of those concepts, like writing a graphical user interface or writing a simple website using some popular language + framework.
If that statistic is true, I would say that they probably understand algorithms very well, can prove the runtimes, know which data structures to use and why, etc. What they can't do is actually implement it in working code, or write anything else outside of those concepts, like writing a graphical user interface or writing a simple website using some popular language + framework.