Well I mean, out of all the Winchesters that there are or have ever been its really only Sam and Dean that are hard to kill and keep dead. And even then it's really only the "stay dead" part that's hard, they die frequently enough. 2 out of 32455 Winchesters...I mean, at this point it's pretty clear God's or some other dude has some money riding on those two for all the divine intervention that keeps interfering in this shit.