Wikipedia is usually pretty good at giving an overview of the situation.
> In September 2010, the majority of outside OpenOffice.org developers left the project, due to concerns over Sun and then Oracle's management of the project
> […]
> In April 2011, Oracle stopped development of OpenOffice.org
But the OpenOffice brand was already built, so obviously a lot of people still think it is the most active project.
Presumably, Oracle did not know what to do with this asset they bought, but they thought they might be able to squeeze value out of it. They believed the only way to do so was to have total control over it, which removed all value from it (except for the brand). Then they put it in an Apache-shaped trash, along with the brand.
Development of OpenOffice continued after it landed at Apache, notably in the form of a large IBM donation of code from Symfony. It is only recently that maintaining the project has become an issue, and as the OP illustrates, the remaining community is engaged and grappling with how to deal with that.
It's important to note, by the way, that Oracle had taken the Star Division developers off OOo and put them on their abortive CloudOffice endeavour. So the outside developers leaving was actually most of the active development resources at the time.
> In September 2010, the majority of outside OpenOffice.org developers left the project, due to concerns over Sun and then Oracle's management of the project
> […]
> In April 2011, Oracle stopped development of OpenOffice.org
— https://en.wikipedia.org/wiki/OpenOffice.org#History
But the OpenOffice brand was already built, so obviously a lot of people still think it is the most active project.
Presumably, Oracle did not know what to do with this asset they bought, but they thought they might be able to squeeze value out of it. They believed the only way to do so was to have total control over it, which removed all value from it (except for the brand). Then they put it in an Apache-shaped trash, along with the brand.