I saw the doc back when it originally aired and have seen it in real life far too many times over the years. Parents like this only make their kids hate them, hate the sport and, I fear, hate themselves because nothing is ever good enough. Coaches are afraid to intervene because they want to keep getting paid. Officials sometimes intervene, but not often enough.
Tell your kids that you love them regardless of the final score. If you're not expert enough to coach the sport, then STFU with the negative shit and let the real coaches handle it.