The Project Zero team is specifically supposed to find Zero Days in other products to make everyone more safe. Google has other security teams for finding bugs in their own products. This isn't Project Zero's fault, nor does it really have anything to do with them. Project Zero is one of the decent teams at google trying to do good by everyone; they can't find every single bug, and if they changed their mission to just focus on Google products we might not have found all sorts of big bugs (eg. heartbleed) for a lot longer. Probably best to leave them alone and let them get on with their business.