Nicely put, the path of the Allfather is quite allot more serene in a twisted sense. Granted more fall into the Allfathers embrace unwillingly then willingly unlike the other gods, but its only natural i guess since its a natural instinct to fear disease and illness. Then again Nurgles "lure" isnt really that charming as the ones the other gods hook their believers with. And still you do have some grumpy pants around and about, like the Death Guard. Granted id reckon thats more to the fact that their entire existence was filled with priding oneself of being immune to everything imaginable, building your legion culture around that. Then it all comes crumbling down, i guess id be cranky too.
I actually find the Death Guards story kind of odd because of that(But not precisely bad, mind you.) because a lot of Nurglite followers are a generally jolly sort, but there has to be another side of the coin. Just like there are Slaaneshi who revel in the absence of sensation rather then it's amplification, and invent things like the Icon of Silence.
Yup, thats why i love Chaos as a faction, it lives up to its name. Everyone can be very interesting and vastly different, even within the perceived limitations of their patron.