Define a dead coin? That is what makes a coin dead enough to make the list.
Pretty easy to figure it out.... I'm not saying the coin is "
officially dead" its just a heads up for people to aware there isn't much going on ...( I'll even check their forums if need be ...)
1.] Non-activity from Dev's can set a certain amount of time.
2.] People can complain to a private PM that the coin has been de-listed at an exchange and is going down hill ...
Probably, plenty of other criteria to go by also....but those two for starters....