This. Even with the Pro or the Boys, which I found kind-of annoying in the middle finger Ennis quite clearly enjoys giving to superheroes and whatnot (especially the somewhat puerile attitude he displays toward the DC heroes in the Pro), there are moments that strike you as utterly honest and utterly real and depressing. Despite the extremities Ennis takes it to, there are vile people in the world and all he suggests is that supermen would be no different, hence the 'suck my cock' scene in the Boys, in which you feel utterly awful for Starlight.
Millar, on the other hand, clearly delights in just coming up with stupidly superficial ideas and having a laugh at the expense of existing characters, like the 'gay' coupling of an alternate Reed and Johnny that he apparently found so hilarious, or the idea that Red Skull is Cap's kid in the Ultimates. There's potential in each idea, but he blows it because he's such a fucking child.