You haven't interviewed enough then.

I interviewed dozens upon dozens of candidates who couldn't describe to me the underlying data structure for a hash table, all with degrees from reputable schools. This was at Amazon of all places, where they did a decent job of filtering before they even got to me.

Don't even get me started on post-grad degrees. Those that have only PhD's or Masters in CS have been especially bad in my experience.

Passing a course, even doing well, is a very different thing than actually internalizing the material.