Why do people think Noah Is untradeable?

Look I like Noah high energy and passion he brings to the game, but come on the dude Is not untouchable, the only player on the Bulls who's untouchable Is the MVP DRose. I think the Bulls will be making a big mistake by not trading him for Ellis, just like they made a mistake for not trading for Melo. Mr energy guy was on the bench In crunch time vs Miami In the eastern conference finals.