I’ve been reading Diana Rajchel’s “Mercury Retrograde Boot Camp Series” (this is no. 9). Some good stuff there.
For this, the practical and metaphysical reason is the same:
You clear your path from things that were scattering your attention. Now, the things that need your attention get it faster. That’s immediately more time, attention and energy you can use for a) the people you want to give your attention to and b) for yourself.
I actually am usually productive during these periods. It is just that everyone else is so damn slow.