FOSS is an activity taken up by people who want a particular solution to a problem. When the tech and IT industry were vastly smaller than it is today, there was actually a larger number of high-quality FOSS projects. Today there are more FOSS projects than ever by number, but a good chunk are what I would call "throwaway" projects. Another large amount are projects that just exist to fill gaps in new ecosystems (a new language/framework/platform/etc appears, and now they need a lot of projects to provide libraries to fill needs). And there's lots of immature engineers who are growing up in a culture without documentation, and too quick to reference snippets than learn a tool completely. Tech itself is changing, and that will (and does) affect open source.
But the existence of open source is self-perpetuating at this point. There isn't really a bubble to burst. FOSS will continue to be here as long as the computer allows anyone to create and share a work for free that can be reused and there is a need for. It is not sustainable, because it does not need sustaining. Anybody with an internet connection can decide for themselves to create open source. As long as we provide an unimpeded means to share their work (newsgroups, mailing lists, FTP, mirrors, etc), there will be open source. And as long as somebody has leisure time, and there are nerds to be interested in programming during their leisure time, some will spend it on open source. It's like "sports": people will still play sports regardless of a business motive.
I think people are shocked by the whole "business source" license thing, but I'm not. Open Source was never a business model, no matter how much some of its proponents wanted it to be. It's taken a while for people to learn that lesson, but it's starting to sink in. The fact that fewer startups will be open source now isn't going to change the open source community at all. The community will be here regardless of what any business (or individual government) wants.
As far as "our reliance on open source", that's just a happy accident. It's free of charge and free of use, so business uses it. If for some reason it stopped being free of charge or free of use, then business would just pay for proprietary software like it used to. I don't see this happening anytime soon, though, unless somebody passes a law banning Copyleft.
But the existence of open source is self-perpetuating at this point. There isn't really a bubble to burst. FOSS will continue to be here as long as the computer allows anyone to create and share a work for free that can be reused and there is a need for. It is not sustainable, because it does not need sustaining. Anybody with an internet connection can decide for themselves to create open source. As long as we provide an unimpeded means to share their work (newsgroups, mailing lists, FTP, mirrors, etc), there will be open source. And as long as somebody has leisure time, and there are nerds to be interested in programming during their leisure time, some will spend it on open source. It's like "sports": people will still play sports regardless of a business motive.
I think people are shocked by the whole "business source" license thing, but I'm not. Open Source was never a business model, no matter how much some of its proponents wanted it to be. It's taken a while for people to learn that lesson, but it's starting to sink in. The fact that fewer startups will be open source now isn't going to change the open source community at all. The community will be here regardless of what any business (or individual government) wants.
As far as "our reliance on open source", that's just a happy accident. It's free of charge and free of use, so business uses it. If for some reason it stopped being free of charge or free of use, then business would just pay for proprietary software like it used to. I don't see this happening anytime soon, though, unless somebody passes a law banning Copyleft.