Not to mention doing away with the illegal-defense rule, which no one understands anyway. What league officials want is more movement, more skill, more of what basketball used to be. It changes the game, that's what. Almost by definition, zones slow games down. They allow teams to focus on stopping one or two players, thus making other players beat them.
Zones create a different game.
Rest assured that Michael Jordan wouldn't have been Michael Jordan if he had spent much of his career facing zone defenses, or spending crunch time being played box and one. It also makes the NBA more of a coaches' league. This, too, is very different. They better hire some assistants who know how to attack a zone. They better start preparing themselves for a changing reality.