Bill - There are many minor injuries that are nowhere near life threatening that still require daily dressing changes. For example a large abrasion or a moderate sized burn or laceration. The bleeding would be easily controlled, but they still need to be kept clean with fresh antiseptics and dressings.
A couple of years ago my bike hit a pot hole and flipped on it's side, and I skidded a couple of feet with my bare arm against the pavement, and it left one hell of an abrasion. It wasn't too painfull and certainly not a major injury, but It was pretty messy and leaked lymph fluid for the next few days. It's not hard to imagine something like that happening when falling down a steep rocky trail, for example. If that happened ona backpacking trip and I didn't have plenty of guaze, it would really suck. I would not want have to rip up expensive clothes to make a mediocre bandage. And an injury that's larger or with more bleeding would require even more dressing and bandaging. I can easily imagine a scenario where a non life threatening injury on a multi day trip would require all the dressing and bandages in the kit, and a lack of them would result in either premature cancellation, or more likely, inadequate treatment(that could result in infection).
Even if the wound is relatively clean, when backpacking the dressing will likely be getting dirty and sweaty. If properly cared for these injuries do not have to cancel a trip, and it would be a shame to cancel a trip just because there isn't enough gauze in the FAK.

By the way, is there a difference between steri strips and butterfly Closures? As far as I know they serve the same purpose.

Massacre - there are electrolyte tabs and powder in the FAK which contain potassium.
Chlorine washed shirts kept in a plastic bag would be clean, but nowhere near sterile. Everything around us is covered in microorganisms, and unless something is completely sealed is is immediately exposed to contamination. If you boiled a shirt for 10 minutes or so immediately prior to application, it would be close enough to sterile, but that's not exactly the most practical solution.


It occured to me that I should explain the difference between a bandage and dressing, for people who may not know. A dressing is something sterile applied directly to the wound, like a 4x4, and a bandage is something used to hold the dressing in place, and is not necessarily sterile, like a roll of gauze. A rule of wound care is that you should tape bandage to bandage, not bandage to skin(in other words, avoid applying tape to skin of possible). Tape applied to skin can be painful when removed and does not stick as well, especially if the patient is perspiring. Generally to properly dress a wound, you cover the area with gauze dressing(after cleaning and applying antiseptic if bleeding is controlled, and possibly non stick dressing), then secure that with a roll of gauze, which is either taped or tied closed. This is more comfortable, stays on better, and provides much more protection for the wound than simply taping on a piece of gauze, and allows the use of a pressure bandage if necessary. I apologize if everyone already knows this, but in my experience some people just don't understand this. The point I'm trying to get across is that dressings and bandages are not interchangeable, and it's important to know the difference.