But it took years for your (now typical) OS, server, and Internet open source projects to reach maturity and figure out how they can be monetized.
People in the sciences should start blogging more. People like me find all of these subjects very interesting but very foreign. And I think many of us have grown a bit bored with where most programming efforts are directed (backoffice, ecommerce, and social apps).
1. Keep in mind for most projects and papers, not very many people are ever going to use the source code. For most projects, there's almost no chance that you're going to get a lively, multiple contributor project going. Odds are it's just going to be on your shoulders.
2. If you're going to stay in academia, there's no level of bragging rights to an awesome project, and it won't particularly help your job prospects - indeed from an opportunity cost perspective, most of the time it will hurt them. Once the code is good enough for a paper to be written, the incentive to do more work on the code vanishes.
3. Science blogging is actually a pretty active field. But talking about the software aspects of code don't get talked about as much because its just a tool. There are some blogs on software for science drifting around out there though.
Clean, well-documented source code won't get you grants. It won't yield citations. It won't get you tenure. Beyond making sure you can run the same code again, and it works if the postdoc who wrote it leaves, everything else is under the "For the good of humanity" incentive structure. And with grant paylines in the middling single digits, its really hard not to triage good code in favor of making sure the lights stay on.