The tooling amplifies the problem. I've become increasingly skeptical of the "open contributions" model Github and their ilk default to. I'd rather the tooling default be "look but don't touch"--fully gate-kept. If I want someone to collaborate with me I'll reach out to that person and solicit their assistance in the form of pull requests or bug reports. I absolutely never want random internet entities "helping". Developing in the open seems like a great way to do software. Developing with an "open team" seems like the absolute worst. We are careful when we choose colleagues, we test them, interview them.. so why would we let just anyone start slinging trash at our code review tools and issue trackers? A well kept gate keeps the rabble out.