That's what open source and peer review are all about. The code speaks for the coder (sometimes the coder gets to speak for him/herself too, when asked), and the community sorts out the competent from the incompetent.

Of course even in this arena, whether a good piece of open source code really gets the usage and notariety it deserves may still be a hit-or-miss, luck-of-the-draw kind of process. (And it's possible that some really poor code gets into the "standard tool set" for a while, but sooner or later, it will get phased out.)