The mini-14 is commonly sold as the prototypical "ranch rifle", to the point where the mini-14 model that has scope mounts is actually called the ranch rifle. In some ways it's the modern implementation of the lever action 30-30 you see in the movies. The rifle is designed to be reasonably light, easy to point, and above all a reliable source of moderate firepower in any situation.
It's only reasonable that a weapon designed to be the one rifle someone in "rough country" might have available would end up with a high capacity magazine. Whether it's short-range varminting, keeping the coyotes from bugging livestock, hunting small game, or simply plinking to keep your skills up, not having to reload as often is desirable.
Think of high capacity magazines in a sport rifle in the same way as you'd think of a remote control for your TV
Not exactly necessary, but convenient as heck.
As a side note, when I was living in a more remote area I kept one high capacity mag loaded in the event a criminal (or some criminals) chose me as an easy target since I was living alone. Since it's so easy and perfectly legal to outgun the average stupid criminal, why not be able to defend myself? I all I have to do is resist the urge to go mad and kill everyone in town, an occurrence that must have been common enough in Europe that they banned nearly all firearms. Thank goodness Americans have enough restraint that we don't need to disarm law abiding citizens because of the criminal acts of the few who can't control their psychopathic urges.
