If the argument is that he lacks offensive skills... DeAndre Jordan averages double digits. Ibaka has much more offensive skill than DeAndre; he can have a bigger impact than what DJ has, if he were in the right situation.
Whether it's the coaching staff or Ibaka, the biggest issue is that he's been typecast as a 4 and the position, in general, has been marginalized into a prop in this spacing obsessed era (and will continue to be until Griffin's/Green's start popping up). Unless he develops the handles/passing to fulfill that role, Ibaka is going to suffer from the marginalization of the 4.
I'm unsure of his strength, but he doesn't lack the size or rim protecting ability to play the 5. He's going to have to be like Horford and embrace the 5 if he's going to thrive and reach his potential in today's NBA.