Because I use Linux Pro Audio tools in my studio and daily life and am involved with testing builds, helping with ports, generally messing around (, break stuff), and occasionally make a tune or two.
I am very happy with the free and open tools I have at my disposal.
Even with the numerous rough edges, duct-tape and hacks to keep some things together.
This is Hacker News, right?
it's hacker news so I expect some actual reasons not hand waving generalities that don't amount to a "hill of beans"