There is no reason for him to leave Chelsea.
He is going to bring them another domestic title. They are in the finals of the FA Cup. A potential domestic double in his first season. He has an owner who has money to spend, and is willing to spend it. He is the darling of London, and a hero to Chelsea already.
Again, what is the motivation for this man to leave?
To go to Inter? 7th place Inter? Of all places. To go to a shit show that he has no emotional ties to. At least when he came to Juve, it was a shit show that he was emotionally vested in. Why the fuck would anyone, in 2017, go from Chelsea to fucking Inter?
Go ahead and tell me "money", and then realize that Roman Abramovich is the owner of Chelsea. The amount of money that Inter would have to spend to even catch up to Chelsea's current roster would be astronomical.