Here's a tip I always give orgs I am involved in. Never base your project on a Mozilla project. Some examples from the real world.
XULRunner - we had a project based on it before I convinced them to go native hybrid with webkit. Good move since later it was dropped and other apps like Songbird were screwed.
Popcorn - one of the dumbest ideas I've ever heard of, creating web videos by live linking other video sources. What could possibly go wrong? All that it needs is the links for the media to never change!
H.264/WebM - what a pointless fight they should have know was un-winnable.
Firefox OS was delusional from the beginning. MS can't get developers for their platform, and they're willing to pay them.
How many dollars has Mozilla just flat our wasted on projects like these? They have the biggest cash cow in the open source world, and they have't produced anything with it other than a browser that is losing it's market share and relevance.
IMHO what the open source world needs is to produce apps that normal people can easily use. What if Mozilla had spent those millions creating an open alternative to the old iLife suite? Imagine your non-techs friends using open source software to manage their photos and music. That would have made far more people believers in open source than the millions they have dumped into dead in projects such as these.