Noone will do that out of incompetence. You don't become a director of Milan or Juve if you're not competent. Galliani didn't "destroy" Milan on purpose. His hand was forced. The same can happen to Juve, considering the financial situation in Italian football.
This still doesn't explain Conte's sudden departure. If there is no money and no ground for success in Europe, then by all means the best serie A coaches should look elsewhere, as Mourinho, Capello, Ancelotti and the likes already did. If that's Conte's reason too, he should have done it earlier, not like this.