The very word "organization" emphasizes the importance of planning, since without planning, there is no way to be organized. In the short-term, planning covers such basic matters as cashflow, staffing, stock levels, and the availability of raw materials. Failing to plan in any of these areas could easily reduce an otherwise flourishing business to chaos.
At the very least, a lack of planning would cause waste. There might be people with no work to do or too few people to perform the necessary tasks effectively. Perishable items might have to be thrown out unused, or there might not be enough such items to fulfil orders. Without effective short-term planning, no aspect of the organization can be expected to run smoothly.
Without long-term planning, it is still possible for the organization to survive day to day and week to week. However, neglecting to plan at this level will soon leave an organization in a directionless and uncompetitive state. It will not be able to secure investment, since one of the first things any investor will want to look at is a clear and realistic projection of future growth. Even more vitally, the business will not be able to develop and take advantage of new opportunities without the direction and clarity provided by long-term planning.