"Cathedrals" using "Bazaar" tactics?

As I read The Cathedral and the Bazaar by Eric Raymond, I couldn't help but wonder to myself: if the bazaar method really is so successful, why it is that large software companies still dominate the markets? It's mostly true that most people who don't either work or play in a technical field use the products of big companies. The truth is, I believe big companies are successful because they are able to put into practice the same principles that have helped open source to be so effective. Since they have large numbers of employees, they are able to generate lots of good ideas quickly. They maintain and build upon the same code base with each release, and with each release their code base is further refined, just like open source code bases are refined over time. They are able to provide effective code revision, since so many eyes see and use the same code. In this way, I can see exactly how big companies are able to stay successful by using the same principles that have given life to open source.