In Microsoft Excel, the labels of a cell are aligned at the left edge of the cell. If you’re dealing with money amounts, the amounts typically line up on the right so that the decimal values line up properly. This makes the math easier. All other values will immediately line up on the left. This allows other values to be looked at easily. It also allows monetary values to be quickly distinguished from other values.
Excel works best with numeric values. If the numerals are large enough, they will automatically align to the left. If they are small or have decimals - as many monetary values will - they go the right. It is that simple, and there’s nothing more to it than that.