The point is that in a real software engineering process, specs and requirements are rarely defined precisely from the start, and the programmer should be able to identify the gaps and clarify them. A generic answer doesn't help as much as a clarifying question.

A common but amateur mistake is to just make assumptions about how something should work and then forge ahead. As a programmer in a company, you are building things for somebody else (your boss, your client), so you need to ask them first.