The algorithm is inherently flawed because it is based purely on authorship of files, and not the quality of the documentation, source code, source code comments, etc.

It doesn't matter if a piece of software was written by only one person. If it has great documentation then the original author can die (or less morbidly just abandon it) and someone else can pick it up easily.

All the node.js modules by TJ Holowaychuk are a good example. They are extremely well written and documented, allowing them to continue being worked on by alternate maintainers even though he has moved away from the Node.js ecosystem to Go.