Sounds like a common software issue. All the features where developed to 80%, and then moved on to the next feature. Leaving that last, difficult, time consuming, 20% open and unfinished.
It’s the difference between more corporate or Enterprise projects and FOSS projects in a lot of ways. Even once that project matures and becomes a more corporate product the same attitude towards completeness and correctness tends to persist.
(not saying foss is bad, just that the bar tends to be lower in my experience of building software, for many legitimate reasons).
It’s “cultural” in a way depending on the project.