User blog comment:HELO/How I Learned to Stop Worrying and Love the Catalyst/@comment-24174486-20120710232656/@comment-24174486-20120712181757

"Because if the Reapers work for the Catalyst, and if the Catalyst is responsible for the annihilation cycle, then the Catalyst is really the main villain for the series and not the Reapers. He’s the head of the snake, the man at the top, the Big Bad, the Final Boss. Unless you beat him, there’s no stopping the cycle."

And yet you stop the cycle without beating him. Because the Catalyst wants you to stop the cycle and wants to help you in doing so.

Calling the Catalyst the "Big Bad" is incredibly inaccurate. The Catalyst is more of a Well-Intentioned Extremist: it created the Reapers because it believed it was the best solution to a dangerous it perceived. When it realized that the Reapers were a poor idea, it resolved itself to helping Shepard end the Reapers' cycles, even above choosing a permanent solution to its "problem" (it could have easily deceived Shepard or instructed them on the possibilities that it supported).

The Catalyst is not an evil mastermind or "goddamn supervillain"—it was a being assigned to find a solution to a perceived problem, decided on a solution that it believed was the best option, and then when it occurred to it that the Reapers were not necessary, decided to help stop the monstrosities it had created.