Accidents can happen people can get run over by a bus, or be in a terrorist bombing incident, or die in a plane crash, or have a brain aneurism.
Whereas Robert Jordan had time to find a replacement author and tell him all the important remaining plot points to get TWoT finished, if there is some sudden thing that happens to GRRM from finishing the books, the end and the main plot points leading to the end are known by David Benioff & Dan Weiss (GoT Producers). So what would you want D&D to do with that knowledge if the worst case scenario happens?
Should they finish the story of ASOIAF only through the TV show? Or should they write (or help someone to write) the final book(s) and then perhaps complete the TV show? Or complete the TV show then finish the books? Assuming of course that the TV show remains sufficiently popular to finish the entire story on screen.
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix
