Do we do practice this technique with other animals or even humans? No. We do have ways of ensuring the maturity of babies in humans through modern medicine, hence allowing us to induce labor and so forth.
But, just because one snake egg pips doesn't mean all are ready to pip at the exact same time. Some may need an extra day or two to ensure or enhance their chance of survival before they attempt to enter the world.
You can say that cutting eggs doesn't harm the newborn snakes, and you might be right. But how can you say beyond a shadow of a doubt it doesn't?