Quite agreed. The view that to be an authentic contributor to OSS, I need to use only OSS tools makes no sense to me. It's not even about my time (although that's part of it), it's about using the best tool for the job. If that tool happens to be closed-source, so be it.

There's been no "fall of open source." If anything, OSS is increasingly the default for tools. And old, closed source tools are being opened up--for example, Microsoft's massive releases of source for their dev tools.