It's a common assumption that a coach or manager has to choose between being demanding and being supportive — as if pushing people hard necessarily requires accepting some cost to their confidence and wellbeing. Carol Dweck's research suggests this is a false tradeoff specifically when the intensity is paired with clear teaching and a genuine, communicated belief that the person is capable of rising to meet the challenge.
The combination that works isn't "demanding, therefore harsh" — it's "demanding, and specifically oriented toward development," which requires more effort from a coach or leader than either pure toughness or pure encouragement alone, since it means holding a high bar while actively investing in helping someone reach it.