Cost has long driven open-source adoption. In 2007, 80% of those surveyed by Gartner cited cost as the primary driver of their open source use. Today, 80% of those surveyed cite the “high quality” of open source as the primary reason for using it, up from the fifth most important consideration in 2011. This has led to more than 50% of enterprises both using and contributing to open-source projects, a massive jump from just a few years ago.
All of this comes down to naked self-interest, of course.