My Dad was like this with me and my brother... Still is in many respects. I've had him tell me I should break up with a girl before simply because she wasn't attractive enough, essentially call me a loser whenever I got even second place at a sporting event and tell me that if I ever received a C, that I shouldn't even bother coming home. We were expected to be the best at everything, which really sucked for me because I'm not naturally good at much. lol. It was really hard growing up like that. But today, my brother is the most exceptional and successful person I know in just about any category I can think of. And while far less successful than him, I do alright for myself.
He's also the only person that ever fully believed in me regardless of what I wanted to do and supported it even if it seemed crazy, so I know it wasn't just solely a superficial thing with him. Without his pushing us, I don't think I would have the confidence or grit that I think I do. While it was hard dealing with it when I was younger, I'm thankful for it now.