I'm pretty sure both came from middle-upper-middle class families. I think we define "spoiled brat" differently. To my way of thinking, that is a person who thinks himself entitled to what he has, and inclined to complain when it doesn't all come easily. That, to me, is Tomic. John McEnroe, by contrast, worked hard at his tennis. I don't think he expected anything, especially. But on-court, he gave umpires and the crowd a hard time. He was sharp-elbowing his way into the top of tennis. It was brash and rude. He's a New Yorker. Around here we wouldn't call him a "spoiled brat." We'd call him an "asshole," and I don't think he'd dispute that he was, in his playing days, and can still be, now.