She is tied to too many characters to assume future writers would not want the character to return. Writing a core character out since the already cast heavy show brought back Jason and is bringing on Lucky, Lulu, the new guy in the hospital -- all of which will be getting solid airtime.
But killing her off in a "she's definitely dead and everybody (including the audience) sees she is dead and her body is buried -- ties the hands of future writers.
For example, while killing off Morgan was dramatic with an emotional impact that still affects the characters -- I could envision some great storylines that would really shake things up if it were possible for Morgan to turn out to be alive.
Soap are a long-term format, and putting a period at the end of a core character needlessly limits what future writers can do.
Karen L.