My take on it is that Linux is about freedom, and for
me that includes
freedom to use proprietary software when I want/ if it's most
appropriate. I use Linux primarily because I like the OS. I also use a
lot of GNU/GPL software and have written and contributed to GNU/GPL
software - which will be what I primarily use if I can.
For me: Windows is crap because it does things behind-the-scenes that
are non-user editable - i.e. installing a load of files all over the
place which can't be removed/traced easily, registry bloat, inability
to lock things down effectively,.
Mac - really forces the user to do everything the "Mac" way. Trying to
do non-standard things is very difficult/impossible.
Linux is very configurable, has performance that doesn't degrade, and
I can usually work out how any single bit of the OS is operating if
needed.
Having proprietary software available only increases the
options/flexibility IMHO.
Of course everyone has different reasons for using Linux. Vive la
difference!
.. Also, I wonder if it's something particularly about "popular"
software that scares people? I don't remember so many complaints about
Mixbus...
James