Unless you are doing a personal project just to scratch your own itch, it is not recommended to have the idea that ProgrammersAreUsersToo. The consequences can be serious:
- Unseen bugs, due to partial debugging
- Bad UserInterface
- Incomplete functionality
This blatantly contradicts the idea of eating one's own DogFood.
Even though saying "only programmers will use this" is a BadThing, designing something strictly for learnability (often falsely called usability) isn't the ideal way either. Some tools are targeted to power users or programmers and and some things can go unsaid. Imagine RegularExpressions designed with the verbosity needed for instant learnability without a handbook. Can you imagine a regex search where you type whole words for every one character operator?