If you have a dependency that is simple and stable, it could appear unmaintained since it doesn't have a lot of recent commits, bug reports, comment history, etc.

If a library author wants to make their package "look" maintained for some reason, they could generate superfluous commits and open and close fake bug reports. This could be a "good" signal to the heuristic, but has no real world benefit or worse-case could be used to lend credibility to a package with known vulnerabilities.