Well. Lets talk proprietary software.
Autocad, which I use on a daily basis, is THE BEST drafting software i have ever used. Nothin comes close to how powerful autocad.
Revit, a powerful BIM, or building information modeler, proprietary, and fucking insanely badass. There is no open source equivilant, and I doubt that anyone could make one.
Autodesk VIZ and 3D Studio Max. You really think blender even stands up to these?
The Adobe line. GIMP sucks. Period. Adobe has created a very nice set of apps. From InDesign to Illustrator. Adobe kicks ass, and noone has been able to create opensource equals.
These are apps I use all the time to get my work done. And I use windows and OSX to run them. The world of linux offers me nothing besides apache and MySQL, which my mac handles just fine. In fact. I don't see why I even run linux as my mac can do everything I need linux to do.
I am not going to cripple myself by only using opensource software.
Proprietary != evil. I am all for the sharing of information when the situation requires it. I see no reason why photoshop should be opensource, or autocad and Viz. What could possible be gained by it? We would end up with a shitload of different distributions of similar products that will not work as well, or be as integrated. Right now, I can build a model in autocad or revit, open it in Viz for texturing and more detailed modeling, and still retain all the building information while mainting a link to the other programs. So if person C has to make some changes to the model in autocad, and I am busy adding textures and animating the scene in Viz, I don't have to start over. The updates will show up in my scene and the workflow doesnt stop. Same behavior in adobes line of software. Wht does gimp have? It doesnt even have layer grouping or layer sets, or non-destructive editing tools, or even decent masking tools.