There's an anime I really like, Gurren Lagann, which perfectly sums up why I hate the idea of bringing Hicks and Newt back. And it's actually nothing to do with maintaining Alien3 in continuity. I love A3, but f**k it, this is how movies are these days: Don't like it? Reboot it. But my problem with it is this: we shouldn't bring back old, dead characters just because we can. It's counterproductive. These characters had their shot, and they left their mark. Let the next generation have its chance to shine.
Imagine if Aliens had dragged back Parker, Dallas, Ash, etc. Imagine if that film had been burdened by needing to resurrect, justify, and nurture characters that were already dead. Would it be the powerhouse it is today? Of course not. Would fans of Alien even be happy to see those characters' corpses dug up from the grave? f**k, no. They died trying to do something.
The strength of Aliens lies in its ability to move onwards and upwards from where we were left off. It works because it didn't try to suck Alien's cock and preserve every ounce of its precious memory. Why we feel the need to do just that for Aliens is beyond me.
It might well be awful for many that these characters died unceremonious deaths, but for God's sake -- they died, let other characters have their moment! We've gone decades without them. We don't need them. Give us new characters we can root for, instead of banking on us still giving a flying f**k about characters that died 24 years ago.