Interesting thread. Lot's of navel gazing, introspection, and life advice. I feel like we should all be sitting in a pub sharing a pint.
Ive is an ex-pat and has kids. It's completely reasonable that he wants his children to grow up in his/their native culture rather than anywhere else. He's British. He wants his children to be British - and not some half USA/Brit hybrid. Take them home and let them eat bangers and mash, play cricket, and learn to speak proper English.
He's proven to be a successful designer and has made a big pile of money for his employer and himself. Good on him. Now take that pile of money and raise your kids how you want, where you want. Apple is just a company, and they just make things. They'll find someone else to make pretty things for them; you'll never have another chance to raise your children.
And Jony's close friendship with Steve could be a catalyst. Maybe he's seen Steve spend monster hours pouring his heart and soul into Apple, Pixar, Disney, etc. Who knows what kind of family life Steve has? Maybe Jony would like a little more family time and a little less company time.
The illusion that you are irreplaceable is the stuff of dictators and tyrants - see Mubarak, Gaddafi, et al.