http://wowpedia.org/Murozond
Now living outside of time, Murozond was once the great Dragon Aspect Nozdormu the Timeless One. After the titans showed him his own death, the tormented Nozdormu was tricked by the Old Gods into trying to subvert his mortality. As a result, Nozdormu shattered the timeways and created the infinite dragonflight... jeopardizing the very future of Azeroth.
http://wowpedia.org/Nozdormu
Murozond is in fact the future version of Nozdormu who will inevitably go mad and try to interfere with the past, thus his past self will send adventurers in to the future to strike him down. Right after Murozond is slain Nozdormu told them:
"At last it has come to pass. The moment of my demise. The loop is closed. My future self will cause no more harm.
Still, in the future, I will... fall to madness. And you, heroes... will vanquish me. The cycle will repeat. So it goes.
What matters is that Azeroth did not fall; that humanity survived to live another day.
All that matters... is this moment."
i just see Murozond's quotes as a mad man that convinced himself that what he was doing was the best for everyone