It doesn't seem efficient to be looking towards the sideline every play, to see if you have to come out, especially against a hurry-up Offense. All the running back and forth from the sideline would pretty much negate any advantage you might have had from resting a player.
It will be interesting to see what happens going forward. They'll probably continue substituting until New England (or somebody else) forces them not to.
They have all kinds of fools running in and out...Leonhard, Bruton, DJ, Trevathan, Ayers, Jackson, etc.
I guess it pretty much fits the Offense, who have Tamme, Stokley, Ball, Hillman, Green, and now Moreno, substituting.