Overview:
Notice how Orochimaru suggested killing the orphans to end there misery. So, had the three been killed what would have changed.
Nagato, Konan and Yahiko die.
The Akatsuki is not formed.
Tobi cannot accomplish the Moons Eye Plan as originally planned.
Seven of the Nine Tailed Beasts are not captured.
Millions of Ninja do not die.
The Fourth Shinobi World War would not have happened.
The Kyuubi Attack might not have happened.
And more.
See how Orochimaru could have prevented these events. Jiraiya stopped him, and further more trained them, ecspcially Nagato to learn how to be a shinobi and kill. Jiraiya is why the Akatsuki was born.
Conclusion:
Orochimaru almost saved the world but was stopped by a 'hero'.
