User blog comment:The Milkman/Shades of Purple/@comment-5287758-20120930050555/@comment-24174486-20121001180418

"S/he/it does control the reapers..."

The Catalyst's ability to control the Reapers is limited at best; that is why it needs Shepard's help to end the cycles. If it could halt the Reapers' cycles on its own, then it wouldn't need Shepard to replace it in Control; if it could order the Reapers to destroy each other, then it wouldn't need Shepard to use the Crucible and sacrifice synthetic life as well.

"How is it deserved? just because I don't want to join their cheap Deus Ex Machina I get one?"

Neither the Crucible nor the Catalyst are a deus ex machina. That term is used for a sudden and contrived solution to a problem in a story; you know well in advance what role they will play in the story and it is only through the efforts of the characters that the resolution of the plot comes to fruition. And if you put very little effort into it, the galaxy ends up paying dearly.

A good ending to Refusal, on the other hand, would be a deus ex machina. It would overwrite everything you see and are told in ME3 that makes it quite clear that the galaxy's forces don't stand a chance in conventional combat against the Reapers—never mind the psychological impact that the Crucible's failure would have on the forces of the galaxy.. It would be throwing away all of the sacrifices and resources that the galaxy put into the Crucible—to put it simply, a complete betrayal—and yet rewarding a positive outcome.