Rufus has as a shitty as life as anyone in this game, it's just that he has all the money in the world, so people imagine he's cushioned from the shittiness. We don't know the details of his relationship with his father, it was bad enough to make him want to kill the old man. Even if his father loved him, he didn't know how to show that love. Rufus inherits the company in a time of crisis, tries his best, is ruthless but not cruel, leads from the front, fails (L for Loser), literally slides from the top to the bottom, is injured, imprisoned, tortured, constantly in pain, keeps his cool, always assumes command, tries to support others, nearly drowns, contracts geostigma, sets up a clinic for geostigma patients and tries to find a treatment, which he distributes free of charge; decides it's his duty to put an end to the toxic legacy of Jenova; underwrites the WRO. He's often sardonic and sometimes angry, but never bitter. If President Shinra set out to toughen his son up and make him resilient, he certainly succeeded.