1. It is being maintained (albeit less active), version 1.9 is in the works. Communication could improve a lot though.
2. What's so hard about maintaining the Meteor project? It's been mostly backwards compatible since versions before 1.0 (released over 5 years ago, when the JS ecosystem was a very different universe). What other JS framework has a comparible track record towards backwards compatability?
3. Third party packages may break and become unmaintained, but this is just as much true on NPM. In the end Meteor is mostly a build-tool (and a pretty good one, with zero-configuration, code splitting, ...) creating a Node application with full NPM compatability.
