And I didn't say it is. Only that it's usually the only way of building a business around GPL software. This is fine for serving some people, but it has a huge blind spot for those who mainly want to write Software and try to live off of it. IMO this is the main reason why Desktop linux never took off - you just don't have enough userland software that's ready for production use in a professional environment - see desktop publishing, audio, video etc. This sort of software is not going to be written as a hobby, it needs full time professional developers and investors who can see the ROI starting at around 1M$.