What is it?

[Sam Akabara]

To understand what the Camarilla is, it is first necessary to understand, on a deep and abiding level, what it is not.
Specifically, the Camarilla is most definitely not the group that contains the Vampiric "Good guys". There is nothing intrinsically good, true or nice about the Camarilla or the vampires who comprise it. The Camarilla does not exist to protect humanity from the Vampiric depredation; rather, its function is to ensure the safest and most profitable existence possible for its members.
The care the Camarilla takes not to make too overt a presence is precisely the same effort the wolf makes to disguise his presence among the sheep.
What the Camarilla is, then, is a sect by the vampires, of the vampires and for the vampires. It exists to protect its members from the surging seas of humanity, who by dint of sheer numbers could wipe most of the Kindred off the face of the earth. The Camarillas single greatest creation, the Masquerade, exists precisely for this purpose. A veil of misdirection and falsehood, the Masquerade hides the very fact of Kindred existence from the Mortal world. What Humanity can't see, it can't kill, and thus the Kindred are safe. The fact that the necessity of preserving the Masquerade cuts down somewhat on the casualties the Camarilla vampires inflict on the Mortal population is merely a by-product of the need to preserve the illusion.
What the Camarilla is really about, though, is the status quo. and the preservation thereof.
The elder vampires who dictate the vampire’s policy LIKE having power. They LIKE having control over hundreds and thousands of younger Kindred. They LIKE having wave after wave of subordinates there to protect them. And most important of all, the want to keep things exactly the way they like them. The Camarilla works, at least for the vampires who make the policy decisions, and thus they direct the sects policies toward preservation rather than improvement. Could the Camarilla work better? Possibly, but then it wouldn’t serve the interests of those who control it nearly as well.
Even those vampires lower down the power structure – Primogen and elders, for example – have a vested interest in keeping things the way they are.
Without the Camarilla, they’d soon perish. The Camarilla provides them with a buffer against the winds of change. Protecting them from an era that has no use for nobles and the like, but every use for coders and technology specialists. By keeping the Camarilla the way it is, they create a comfort zone for themselves by wrapping it up in offices and traditions, keeping the Camarilla on a level they can operate on.
As for the younger Kindred, the Camarilla offers them, in a word, security. The sect is protection while the vampire comes into his or her powers and learns the customs of their new existence.
It is a group of allies against the moral world and other vampires, a shelter against the new and terrible perils of unlife. While that security can quickly grow oppressive, in the beginning it is worth a great deal to newly embraced Kindred, who would otherwise be completely and utterly alone.