Well that's easy to prove you wrong.
Take Linux audio, for example. Not pulse audio or drivers or anything like that... that's desktop stuff. I am talking about using Linux as a digital audio workstation and having good applications for doing studio recording and music creation.
For a very long time Linux had lots of capabilities in regards to audio creation and editing, but it was all very difficult to install and use. Stuff was distributed in source code form, there was no way to use it all together.
Then along came the Angula project. The Angula project was a initiative to try to produce audio specific Linux distributions based on Redhat/Fedora and Debian. The Redhat/Fedora side didn't really end up going anywere, but the Debian side was fairly successful and was called 'Demudi'.
What this did was to clean up a lot of the applications and ended up helping the standardization around JACK daemon. The Jack daemon allows for a very low-latency, high-performance method of routing uncompressed audio and midi signals from application to application and to and from external devices. So people can now easily install the software, and with a bit of work, develop their specific workflow using a mixture of hardware, software, and multiple audio applications, that rivals anything you can get out of Windows or OS X.
This lead to those packages from Demudi to being accepted as part of Debian proper and from that grew distributions like 64Studio*, which are used in real-world commercial DAWs and such things. (and UbuntuStudio, of course. But I like 64Studio a _lot_)
* 64Studio is a commercial Linux distribution that focuses on being 100% open source/free software. They make money by support and distribution customization. Very cool stuff.
http://www.64studio.com/