What is the decision the council of gods makes about mankind?

In Utnapishtim’s story, the gods give no reason for the flood. The decision appears to be arbitrary. In some older versions of the story, Enlil complains that humanity is too noisy and prevents him from sleeping. This appears to be a character trait of Enlil as he also decides that Enkidu must be the one to die, also without a concrete reason. Utnapishtim also does not ask the gods why the flood is coming.