User blog comment:The Milkman/Mass Effect in Retrospect/@comment-3228423-20130419042401/@comment-4950455-20130420055025

Er... we don't actually know that it didn't have the Catalyst - all we know is that it didn't have the synthetic-organic conflict backstory. It's quite possible the ending would have played out essentially the same, except with a far more nonsensical motive for the Reapers and significantly worse final "choice".