and in the process they care a little less about usability for others...
deejjjaaaa, "others" is a very broad term, there is many different levels of "others", but they all are welcome to participate in the project and contribute - either by sharing thoughts on improvement and then actively participating in testing and writing documentation or even coding...
RT has gone through a high rate of expansion in the number of tools, in quality of tools, in workflow enhancements, etc.
There are some major architectural changes that may be implemented in the future to allow more flexible implementation of features and would eventually lead to a refinement stage when RT will get further polished out - in GUI and in the engine. But all with time, as there is a significant constraint on development resources.
Usability-wise, RT has already gone through a great number of enhancements (just search googlecode issue list by the issue type)
and it will require more time and effort to refine it further. There definitely is a desire to do it within the team, but it requires vision, design and implementation.
For comparison purposes, here is Lightroom release schedule(http://en.wikipedia.org/wiki/Adobe_Photoshop_Lightroom
Version 1.0 February 19, 2007
Version 2.0 April 2008
Version 3.0 October 22, 2009
Version 4.0 March 5, 2012
How long would one have to wait to get a bug fix or any new feature to be implemented in Lightroom? This is with Adobe's resources.
Within RT - in some cases it is literally next day, and usually between 1 to 5 weeks!
I am strongly motivated by the spirit of rawtherapee team, it is remarkable how productive the team is with the democratic approach.
There is a steering committee, and it is comprised of both developers and not developers, based on contribution into the project and, specifically, dedication to it.
Users are absolutely welcome to contribute in many ways possible and it will lead to an even more user-friendly:) state of the art program.