I think there may be some merit to this.
First, it makes the tax structure for companies a lot simpler. The amount of paperwork for tracking all of your expenses is silly (I _hate_ saving and tracking receipts) and you don't know how much your tax will be until you know how much your profit is. If it's a percentage of revenues you can just figure it in to your costs and be done.
Second, the tax on income penalized businesses saving. So, if you need to make a big investment that you can't finance out of revenues in a single tax year it makes more sense to borrow for it than it does to save profits for a few years. When times are good, borrowing is fairly easy. However, as soon as a recession hits, banks start to trim credit lines and refuse to make new loans. This decreases investment and makes the recession worse. If more businesses were financing themselves out saved profits the business cycle would probably not be as much of a boom/bust as it.