I read all these threads about coins becoming officially dead. However, most of these threads are FUD. When does a coin become official dead? Is it when the developer stops developing? Is it when the coin stops trading on major exchanges?
An altcoin officially becomes dead when its blockchain stops advancing. That is the heartbeat.
I think this is the best and right descriptions,any coin can be adopted and relaunch,because majority of this coin are open source,I have seen some coin adopted,bitcoin developer is not around anymore but his works continue because people are adopting it.