[nirvdrum]

Not to get all philosophical, but "legitimately a bug" is a hard question to answer. Some people strictly consider correctness to be the definition of a bug. Others extend the definition to mean when things don't work the way they probably should (e.g., performance or usability). Performance is an especially interesting one to me because if it's not really a bug, then does a performance regression constitute a bug even if it's producing the same results? If someone is relying on that timing or it otherwise affects interaction with the code, its execution speed is a functional component.

In my experience, projects that adopt a slightly broader definition of "bug" have a better track record of improving on those fronts. Nobody like to have bugs around, after all.