I don't think so at all. It's training us to be able to use the frontal lobes in stressful situations, instead of reverting to more base thinking and reacting.
The way this one famous boxer won his fights was by making fun of his opponents, getting them angry, so they would revert to a more reptilian mindset and not be able to use higher cognitive thinking. I doubt one would want, when attacked, to not be able to think well, and just revert to fight/ flight.
The breath can also be used as a way to be able to use the upper vagal way and gain access to the fronal lobes. Some think this is why meditators often use the breath as a focus.