One of the reasons I huted almost exclusively with my Rem 870, when I could have used a rifle, was because we use 870s at work. The thing is at work I don't get to shoot live moving targets like I do while hunting, so even if only one shot is fired - it adds to the training so to speak. It also keeps me very familiar with the 870, and gets me used to lugging it around if I ever need to do it at work.
Another reason I used it, more so than the above, is that I would never feel as comfortable if I ever missed with a riflle as I could if I missed with a one ounce slug. The slug will not travel nearly as far as many rifle rounds and therefore there would be less of a chance of hitting someone way off. There were often trespassers on my uncle's farm, and now I hunt public land since he sold the farm. I am nottalking about hitting someone I can see either, as I am fairly certain that will not happen because I am careful before shooting, but rather shooting someone so far off they cannot be seen. I know the chances are small that such would happen, but it is something to consider.
The biggest reason, more so than any of the others combined, is that I wanted to be quite sporting to make it a fair hunt. I have only shot about 8 or 10 deer in many years of hunting. Sometimes I had great shots on does but no doe tag. Other times I had an iffy shot on a buck or doe but would not take it because of the iffiness. Once or twice a great shot on a buck but I wanted bigger (the heck with that now I want venison).
Other times I got the deer to where I wanted them - within 50 yards, and better yet within 35 yards. I like the challenge of getting them that close in before shooting, not because I would not be able to hit them further out, but because of the chalenge and because of a desire for a fair hunt. It is not all that easy getting in deer that close when you hunt on the gorund, but I have gotten them as close as sniffing me from about 2 or 3 feet (no I did not shoot it).
Guess I am getting off topic a bit here, sorry.