There is a gracious plenty of newsreaders on Linux, but the BeOS still doesn't have one worth using. All other things being equal, a smaller program is better than a big one because it achieves the same result in a smaller space.
Efficient programs use fewer resources and run faster.
A good program exhibits a structure and flow, even when they are very complicated. Good programs can be extended and enhanced without requiring a major rewrite. Good programs anticipate the unexpected and gracefully handle problems. No program can be considered finished until the documentation is completed. And yet the vast majority of Open Source projects suffer from incomplete, inaccurate, or missing documentation.