No I do not think beginners should run mostly easy miles. I think they should start with intervals to increase the VO2 max, strength and so on and THEN be able to run easy miles and increase the easy milage, keeping intervals as at least 2 workouts a week.
Easy running gives a slower performance increase and if running too much easy miles too early, injuries can happen.
We need basically two things from running training: 1 to increase the VO2 max/anaerobic threshold/aerobic performance and 2 to condition the ligaments etc and the legs to endure running a lot and to train running economy. 1 is trained best in the start with threshold or harder intervals and 2 is trained best with running a lot of easy miles.
So:
1. Start running intervals or fartleks alternating 1-2-3-4min hard efforts (hills are perfect with low impact) and 2-4min of easy run/jog/walk. 2-3 times a week will boost well, and this should be kept at 2 times a week at a later stage, even though I would have eased down the effort a tad after a couple of months to a more comfortably hard effort to not burn out the motivation (around threshold is good)
2. As the aerobic capability and the leg strength is boosted, the ability to run at an easy effort is increased and more and more easy runs can be added. As long as the total volume of training is low, easy or moderate effort is fine. The more milage the more important to keep it at an easy effort.