Do you believe that you can reason about a computer? I'm going to assume yes. If you'd rather your computer do the countable number of things you know it needs to do, before it draws to the display because it's faster. That's only because you know thoes things exist, and how long they should reasonably take. Most users can't count them, nor do they trust their computer. The loading screen does satisfy them because they know the computer hasn't randomly crapped out... *again*. People who don't understand how to fix computers don't trust them. Rightfully so, they generally dont do what their owner/users want, and randomly will just break costing more money, for seemingly no reason. Those loading screens prevent some of the anxiety of using something you need when you don't understand any part of it.