User blog comment:The Milkman/Indoctrination Theorists Say the Darndest Things/@comment-3469974-20121021084225/@comment-4237253-20121023030126

We do have evidence. Through deductive reasoning, we can ascertain that because destroying a Mass Relay (thus releasing the energy within) causes a supernova, and activating the Crucible destroys the Mass Relays, the other relays will share the same fate as the Alpha Relay. Also keep in mind that the destruction of the Mass Relays may not have been intended by its creators; keep in mind that this was built by various species over a span of would could be several millennia. Also keep in mind that it is the Catalyst itself that notifies Shapard of this caveat; if they didn't know, it likely wasn't in the plans for the Crucible.

The problem here is that you're thinking literally and technically, whereas this is a literary problem. The narrative failed to subvert previously established lore. Could it be possible that this was a different kind of destruction? Well, this is fiction, so anything is possible. However, not informing players of this causes confusion; we cannot make leaps in logic and assumptions. You're thinking from a more in-universe perspective. Try to understand the feelings of those who experienced the story, and reasonably deducted that destroying the Mass Relays could very well annihilate life in the Milky Way. All it would have taken was a simple line of dialogue explaining why this time is different.

BioWare took note of this mistake however, and rectified it in the Extended Cut. This made the narrative more understandable and thus, more enjoyable.