Everyone has a fixed amount of fierceness. The only question that matters is where we aim it.
Point it at people and we get fear. Fear produces compliance, and compliance produces exactly what was asked for and nothing more — which is why frightened teams ship mediocre work and nobody can quite say why. Fear gets obedience out of a room. It has never once got excellence.
Point it at the work and the standard rises while people feel defended rather than hunted. "Nobody here will let this go out broken" lands as care. High standards, aimed correctly, are a way of looking after the team.
Those two directions come from the same place: one obsession, facing different ways. Which is why the people who love the craft hardest are usually the gentlest with the humans making it.
Hard on the work. Soft on the people. Almost everyone gets this the wrong way round.