And that types most of these effects as necrotic, which is not the case. I would not have any problem with a necrotic aura, something visible that the players can work with and around. Although, honestly, I would associate it to other creatures than Ghouls, wraiths, for example.
Well, Spirit Guardians does this in 5e, but it's correctly described. The description, the narrative comes first, then the effect which explains what the cool visual effect does. Here, as is often the case in 4e, it's technically interesting, but this is clearly what came first, and there was not even a strapped on narrative, just a name that does not make real sense.
And for minions, there is not even a narrative, they are just there technically so that the players can kill them quickly.