Maybe that's what makes the Omega label so desirable to some readers? Once their faves are declared Omegas they will always have a place, even if in just some list on a datapage, while someone like Sunspot don't have a guaranteed place unless they are amoung the writers or editorial faves.
Wolverine is the exception, even if the writers hate him he got a place, maybe on a shitty book, but still.