Sadly, some people refuse to work if they aren't using photoshop/illustrator/autocad/etc. But yeah, I'm with you, I use gimp and inkscape but I'm no professional.
I truly believe Adobe holding back their products is one of the largest roadblocks linux has to get widespread adoption amongst the design/developer community.
A lot of the more "arty" people I know would consider giving them a Windows computer to use as a personal insult and would probably be more open to switching to Linux than Windows.
Getting arty people to use desktop Linux could be a huge net positive if they decide to help "pretty" the place up a bit.
[1]: http://elementaryos.org/ [2]: http://elementaryos.org/docs/human-interface-guidelines [3]: http://elementaryos.org/discover
I love blender though, my 3D tool of choice so at least 3D artists are well catered for.