Why Free and Open Source Software?
Let's keep some arguments in favor of free and open source software here.
Cost versus Freedom
The Four Freedoms
Ability to Study Software
Ability to Run Software for Any Purpose
Ability to Modify Software
Ability to Distribute Modified Software
Business Reasons for FOSS
The philosophy of software freedom / free software is a big enough reason for many individuals to choose FOSS. Many believe that FOSS is important in its own right, and that the "four freedoms" mentioned here are reason enough to prefer FOSS.
However, businesses typically do not choose software for philosophical reasons - or at least not philosophical reasons alone. However, it turns out that FOSS has many practical advantages for businesses, developers, and operations folks. Indeed, one could argue that it was practical reasons that caused Richard Stallman to set out to promote software freedom in the first place. Had Stallman been able to print happily we might not have the GNU GPL today.