Ok, realistically now, let's say you're the producer. It's your money. You can continue Scott's prequels, but even if you do, they will lead up to the first Alien film and then in sequence, you're back at the end of the series and all you can do is continue where Ripley 8 left off. Sure you can go back and do a side-quel like Isolation or Cold Forge (which you can always revisit for sure money more or less) but ultimately you still get to the moment in the series where you continue in a post Resurrection reality. By this time, Sigourney Weaver is too old to play a super human alien hybrid. So realistically you should have made a Resurrection sequel earlier, but how do you even promote such a film? You're giving people an answer to a question nobody cared to ask. Who would you even get to direct that? Who would want to?
You're faced with diminishing returns if you continue post Resurrection or post Alien 3.
And...
You have the option to use some of the key actors who survived from the most popular film in the series, and they're willing to continue where that film left off.
It's your money. What are you going to do?