I agree in that OSS is good, but I also think that it can't solve every problem like some GPL fanatics think. I also think that GPL licence works like a virus and that LGPL is much more friendly with commercial OSes.
GPL may work well in the server market where you pay for the support because linux is complex, but do you really think that if let's say ArtEffect5 was released as GPL many people would buy it? I seriously doubt that the authors would get many sales because most of people would create a new version changing a little the sources and the authors wouldn't get new sales... remember we are in a small market and although people won't live thanks to a program sales it makes the coder slightly more happy and motivates him a little to keep on coding.
I don't think that changing GPL software and trying to sell it is a good idea.
