Uh, most studios do take breaks. There are only a few studios that do long-running shows consistently: Toei (Precure, Dragon Ball Super, World Trigger, One Piece), Oriental Light and Magic (Pokemon, Youkai Watch, Future Card Buddyfight), Shin-Ei (Doraemon, Crayon Shin-chan). Naruto is the only long-running show that Pierrot is doing right now; since Bleach ended, all of the other shows they've animated have been a year maximum (and that only for Polar Bear Cafe and Gaist Crusher).
It's not a studio thing per se so much as, when an anime series has been going on for years and years and is still making money for the producers, there's a vested interest in keeping it going. Since the main Naruto manga is done, there's no need for the anime production team to take a break so the manga can catch up - they can just adapt the remaining manga material. But the producers want to delay that, because they don't want to give up a proven franchise. Hence the large amount of anime-original material that's being done.