User blog comment:Caramellson/Try Honesty?/@comment-4237253-20120913021619/@comment-24174486-20120913111828

"......and the Crucible you spent the entire game constructing would be able to do so much without the Catalyst likewise."

Exactly. The game's main plot is gathering the parts of the MacGuffin to stop the Reapers. Thus it is not a deus ex machina.