I always say that its because of that PG 13 rating and the pacing of the story. It felt like we were on a timer, have to go to point A to B without even expanding a bit more on the characters and the setting. For example, I do love the dialogue between Lex and Weyland, both showing how Weyland isn't just the CEO of a major corporation, but a man who has to be actual respectable reason to why going, wanting to leave a huge contribution to the world, a legacy to be proud of. Like an actual human being and not a 2D cartoon villain. And the fact the old man gave a go against Scar was actually kind of sad but admirable. Something to get me rooting for these guys other than just survival and cuz the movie told me to. It was always a "goddammit" movement with me when each character died off in Aliens, cuz how badass and human these folks were.
And just like everyone else, that damm PG 13 rating had to dumb down the violent nature of both the Alien and the Predator. I wanted some spine ripping or disembowelment, pure creatures of predatory and deadly nature. They had them so held back, it sucked.