"...nobody can really ever “design” a complex system. That’s simply not how things work: people aren’t that smart - nobody is. And what open source allows is to not actually “design” things, but let them evolve, through lots of different pressures in the market, and having the end result just continually improve.
And doing so in the open, and allowing all these different entities to cross-pollinate their ideas with each other, and not having arbitrary boundaries with NDA’s and “you cannot look at how we did this”, is just a better way.
I compare it with science and witchcraft (or alchemy). Science may take a few hundred years to figure out how the world works, but it does actually get there, exactly because people can build on each others knowledge, and it evolves over time. In contrast, witchcraft/alchemy may be about smart people, but the knowledge body never “accumulates” anywhere. It might be passed down to an apprentice, but the hiding of information basically means that it can never really become any better than what a single person/company can understand."
Linus Torvalds, http://www.oneopensource.it/interview-linus-torvalds/