[boost] Are there libraries without ACTIVE maintainers?

Hello. I think it's very important question: are there libraries without ACTIVE maintainers? For what? Because without active maintainers we can't guarantee quality of the libraries. Is Boost community sure, that for all Boost libraries there are active maintainers? E.g. see on Boost.Property_tree - on Github repo you can find a lot of "dead" pull requests without any answer. What should we do with it?