I once worked for a company called Great Bridge, which attempted to make money selling a boxed version of PostgreSQL. We employed/contracted with several key PostgreSQL developers, and I distinctly remember discussions with management and at least one of those developers about this very topic. The developers had agreed amongst themselves and with Great Bridge management to limit the number of key committers who took money from Great Bridge in order to ensure the company didn't exert too much control over the project (I'm sure we would have been happy to have every one of them on the payroll). History proves Monty wrong on this one.

There are many instances where OpenBSD developers indicated that a bug found in one port led to discovery of problems that affected several other platforms. It seems in this case that multiplatform support is beneficial, and the larger the number of platforms, the greater the likelihood that such bugs will be found and fixed.