It doesn't hurt that a lot of managers have no idea what to expect from programmers and no idea how to find and attract good programmers. They seem to learn to cope with whatever they can get and learn not to expect much.

And I have a theory: there's a group of people who have picked up patterns from a bunch of examples they've found on the Internet, or in code they've managed to be allowed to work on, and they've never grown past that. They're fine as long as you're asking them to do something they've seen or done before (for generous definitions of fine), but completely screwed the moment you venture out of that zone and consulting the Internet draws a blank. They can memorize patterns, but haven't learned to think through anything more complicated than that.

These people can appear productive to the right people, yet be completely stumped by FizzBuzz.