Quote Originally Posted by Hulan View Post
Releasing API docs would take almost none of their time, and would give them a new pool of player input to draw from.
Yes and no. Exposing API to users/3rd parties means you have to account for any securities/vulnerabilities in it. There's more work that needs to be done there besides just opening it up and documenting it. But

Not to mention, if they really wanted 5 stars, they could open up a add-on submission form and steal our ideas for the main UI in beta. I don't mind, seriously SE, take any and all of my ideas (for FFXIV).
I've said it before and I'll say it now. Opening up the API does the vast majority of the work for SE. Design, collecting feature requests, testing, refinement, etc is all crowd sourced -- done by the community. All they have to do is take the popular/useful addons and implement them as is into the default UI once in a while, and they'd be able to keep an up-to-date, competitive UI with much less effort.