Orochimaru is a dark reflection of the village itself.
Konoha gets both his parents killed in war, his trauma makes him fixate on death and loss, goes to any length to keep them away.
Forbidden jutsu are created, Orochimaru develops them further and uses them to enslave their creator and against the village to shatter their facade of peace.
He lures Sasuke into seeking him for power, which Sasuke chooses to even after Orochimaru was defeated and weakened. This is a further humiliation for the village that they could offer the last Uchiha less than a broken Orochimaru.
And as the creation of the hidden village system was a desperate gamble to get out of the warring states era, Orochimaru is desperate to escape into a new mode of being where he can finally experience peace.
He is a foil to Jiraiya, who desires a shinobi world shift towards peace but is only a cog in the machine. In comparison Orochimaru is a true revolutionary in that his research can fundamentally change what is accepted as inevitable parts of life.