Certainly there is a Market for the Gung-Ho Action of the Comics, and they certainly provide Entertainment as do the Video Games.
I feel a lot of the times its kind of the same Plot/Tropes repeated so you maybe sometimes get more Variation between the Starship Trooper Movies.
I do think a Action like Movie or TWO could certainly have a Market, and depending how they are done they could be Interesting but i am not sure for Example if we had 4 Alien Movies where they are basically the Same/Similar to say Aliens and Alien Resurrection. Its nice to see something NEW and different explored within the Franchise, and this does-not also have to mean as far as Movies but also Comics and Games.
Most Expanded Novels and Games and Comics deal with the Cameron's Xenomorph look and behavior, and i agree this is because that Style is most Recognized as ALIENS is the most Well-Known of the Franchise. The Prequels have kind of given us the option to explore different kinds of Morphs, the Deacon, the Hammerpedes, the Neomorph are all examples and you can have so many different kinds, with Imagination and Different Procreation Methods... that it would be interested to see these Explored in Comics and Games.
Regarding the Colonial Marines... they are not SOLELY a Military Force purely to deal with Xenomorphs..
I had a Idea for a Colonial Marines TV Series that would be 8-10 Episodes the First 2-3 (2 Hours) could deal with the Recruitment and Training and get us to BOND with the Characters. Then its a case of them having their First Mission which does-not have to be Bug Hunting Xenomorphs. Your not Limited to just them, so you would call the Colonial Marines in to deal with.
*Other Human Conflicts/Warzones.
*Terrorist Activity/Sabotage.
*Rebellious/Out of Control Synthetics.
*Rebellious Colonist.
*Hostages/Assassinations.
You could introduce Corporate Back Stabling, Treason, Treachery and Conspiracy.
We could see some other kind of Bug Hunts....
We could see the Marines Relax on Arcturus and find out what is Arcturian Poontang
So there is scope for Colonial Marines, TV Series, Games or Comics/Novels that dont revolve around Clearing Out Xenomorphs