Don't blame the OEMs
Google, with its perpetual attention deficit disorder, never sat down and thought properly about an update mechanism for Android.
Android Wear devices are also bitrotting. It's not as if they didn't know there was an update problem before designing AW.
Once is carelessness, twice is on purpose? It seems obvious that Google doesn't care about OEMs, they just want the advertising. Cheapy Chinese manufacturers don't care about Google, they just want an OS to stick on it. It's not a future anyone particularly wants.
Silver's cancelled, and the conclusion is that Google has won? I hope not. Perhaps western OEMs will switch over to Tizen or something. It'd be in their own best interest.
If Google ever rock up in court complaining about Dalvik runtimes it'd be funny.