User blog comment:Masseffect7/Mass Effect 4 - No Connection to Shepard/@comment-1786741-20131020213539/@comment-1786741-20131021001428

Another thing they need to take into account is the fate of the races. During ME3, quite a few races can be either rendered extinct or altered in some significant way. You have the Krogan and the genophage, the Geth/Quarian conflict where both can be essentially destroyed, and even the hanar can have their homeworld destroyed by the Reapers. Then you can have endings like a low EMS Destroy ending which essentially destroys Earth.