I am a correctional officer so I can offer some perspective and real world observations. I can assure you the majority of us would prefer no weapons that could be turned against us. Especially firearms. Most inmates are logical. Most want to serve their sentences as smoothly as possible, especially those with long sentences. You have an alpha with Dillon. This happens in real prisons. With no gang presence, and the typical strong bonds of inmates that choose to stick together, it makes perfect sense. I doubt Andrews and 85 would want to have the added tension of being the only ones with access to weaponry hanging over the heads of the people they live with every day. Prisons don't even let weapons in the same area as inmates in the real world. They are in towers or outside the secure area. In corrections you have to have an ability to isolate individuals in order to control them when the stakes get high to even bring weapons to bear. There isn't a system to lock inmates down, or control their movement on Fury. It has to be a voluntary community. This is one. We have inmates waive parole in order to achieve treatment goals, and sometimes spiritual ones.
The inmates elected to stay there with a spiritual goal in mind. It's presented as a tenuous situation, and boils over with Ripley's arrival. Women were never part of the plan.