It's not about open source or not. As I said, open or not is
just a strategy. As the customers are developers, some of them
are capable to identify problem and contribute a fix when the
source is open. This helps the productivity and reduces the
maintenance cost. You can still sell license, service, consulting,
education etc. when you open source. Now I am not saying every
company should open their source, it's up to them. But open source
does reduce cost and attract more users in the long run.
M$ is evil in the way that it doesn't count on better technology to
beat you, it counts on OS monoply to beat you. Of course in many
cases it backfires too.