For me it was definitely more along the lines of returning characters, than an action-oriented plot. Let us not forget that for all the action that was in Aliens, Cameron really did a good job delivering some scary moments of his own. And I don't just mean big moments or set pieces. I'd dare say the ping of the motion tracker is one of the scariest sounds I've ever heard in a film. I mean, the distant howl from "an American werewolf in London" was a scary sound effect, but when that motion tracker goes off in Aliens, the nards go tight.
The inclusion of Hicks and Human Ripley in Alien 5, would necessitate the need to retcon Alien 3. Chocking that film up to space dreams, would be a rather poor way to do it, in my opinion. Then you have the whole business of them being much older, and you're basically continuing the "evil company" theme as well. If that happens then the Alien slips swiftly into terminator territory. This is a quality and much beloved franchise. Those characters that are gone should stay gone. In an entire fictional universe, with billions of humans, there must be one interesting character out there in the vast cosmos. The Alien is an unstoppable force of evolutionary evil, it stands to reason that even Ripley was gonna die at some point. To survive these things over and over is simply unrealistic, and if you want the franchise to continue indefinitely, you have to make plans that don't involve using the same actors again and again.
Alien 3 was a very under-appreciated movie for its time. It took the series back to its roots and made Ripley confront the inevitable. I'd say it sealed everything up rather nicely. Retconing Alien 3 and bringing back main characters means one thing, you're having to build the movie around those characters and their motivations/storylines. Consequently, narrative creativity is reduced, and we lose an opportunity to experience something truly original and unique. We'd actually be losing Alien 5, and getting Aliens 1.5