Just because some things suck, for now, doesn't mean open source is being killed. It means software development is changing. It'll be harder to distinguish between a good faith, quality effort that meets all the expectations of quality control without sifting through more contributions.
Anonymous participation will decrease, communities will have to create a minimal hierarchy of curation, and the web of trust built up in these communities will have to become more pragmatic. The relationships and the tools already exist, it's just the shape of the culture that results in good FOSS that will have to update and adapt to the technology.