Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why don't companies underestimate their earnings to make quarterly reports look better?
You need to distinguish a company's guidance from analysts' estimates. A company will give a revenue/earnings guidance which is generally based on internal budgets. The guidance  may be aggressive or conservative - some managements are known to be conservative and the market will take that into account to form actual estimates. When you see a headline saying that a company missed, it is generally by reference to the analysts' estimates. Analysts use a company's guidance as one data point among many others to form a forecast of revenue/earnings. The idea behind those headlines is that the average sales/earnings estimates of analysts is a good approximation of what the market expects (which is debatable).