In looking at some usability differences between two different products from the same company (one far more user friendly than the other), it struck me how one seemed to be held to a much higher standard of usability and stability than the other. Now I know this could be due to different product teams, different budgets, product maturity, etc, but I also found it interesting that the less usable one was for developers, and the more usable one was for designers. And I wondered why the company would be willing put their brand on two products of such disparate quality. I know that if any designer encountered the issues that were prominent in the developer tool, without the software savvy of a developer (and that innate desire developers have to understand how things work), they would be far less tolerant of these issues.
And then I started thinking of other examples of websites and applications and other software that illustrates how so often, tools targeted at more savvy users are less usable. But developers (or experts of any nature) need usability too! Of course, advanced tools are often more complex and require more learning curve, but there is a difference between usability (efficient and streamlined user experience) and learnability (low learning curve). Advanced users don't need the learnability: the wizards, the step by step walkthroughs. But they most certainly still need and value the usability; and often demand efficiency, for which a streamlined user experience is imperative. They may understand the cryptic errors, but that doesn't make them like them any more!
I know I have been guilty of shortcutting usability on an application because I know the users can "figure it out". But that's WRONG, WRONG, WRONG. Your advanced users are as likely as anyone to appreciate, and even expect the attention to usability.