Anytime you leave the animals on a pasture for more than about 3 days (the longer this graze period, the more pronounced will be the impact), they will tend to selectively come back to regraze (take a second bite) on plants that they've already taken the "first bite" off of, as they recover... and will then tend to selectively LEAVE those less desirable, more mature and more lignified plants. A 60, 90, or 120 day grazing period on a pasture will then result in more "selective grazing"... with animals choosing to eat the most desirable plants and bypassing the less desirable ones. If a manager were to instead crowd them down so that they only have enough forage (when taken down to the most desirable level) for one or two days BY TAKING JUST THE TOPS OF ALL THE PLANTS, they WILL learn to graze much less selectively. They know that tomorrow, you'll be giving them a fresh ungrazed forage area again, so they will learn to take all the tips first and thereby be satisfied, with each day's move. A 12 hour interval could be even still more effective... but of course you have to manage the cost/benefit, taking into consideration the labor requirement of this more rigorous strategy.
What I hear you saying Brute, is that you feel there is a better "cost/benefit" ratio to a strategy that uses longer graze periods followed by much longer rest periods, than had been employed in the "rotating often" scenario you described. Regardless of the length of graze, MOST managers tend to not allow enough/under value the importance of REST.