He became Jack 'King' Kirby because Stan 'the Man' Lee put the nickname in place. Jack was tagged 'King' because his last name started with a 'k'. If he'd been Jack Firby, Stan might have named him Jack 'Flaming' Firby, the hottest comic artist around. Although, you probably wouldn't be saying "He's not Jack Firby. They call him 'Flaming' for a reason."
I'd still take a classic SA Firby over Lee.
I really like Lee's art, but some of his DC work is really priced high for being published just last month. I Albert would lower the prices, I'd be a buyer.