There are practical considerations, where the blade passes underneath it tends to compact the soil at the bottom of the trench. We have Weald clay for sub soil, a compacted layer means a water barrier, better the cut face is vertical and the base broken off. Taking the trouble to give the clod an extra stroke or two with the spade will chop the roots off any weeds and break up that cut face anyway.
I dig as little as possible, but there are times; some weeds have root systems that must be dug out, rotavating chops them up and works as root propagation. Sometimes gardening is a very cold blooded business, one needs to eradicate the enemy in detail, a fast sweep through will leave pockets of resistance that will be a thorn in your side when trying to implant a new culture, best do the job thoroughly before importing the outsiders.
I prefer to use hand tools on the soil, I can hear the robin singing, I am more aware of the world around me and the soil’s condition, my fingers don’t tingle, my ears don’t scream afterwards, and taken gently digging is pleasant, exercise, why should I avoid it? Slow and steady does it, go at it like the devil and you end up at the osteopath having your back straightened, and often a hand fork and a kneeler to take out weeds and turn over the top inch or two is plenty, no need to break up the soil’s structure, but you won't know that if you are wrestling the handles of a noisy machine and breathing its exhaust.