Logo's are just a distraction from the game itself.
No. Not really. No more so than logos are a distraction from a movie or TV program. They all have them. They are on your CD's that you purchase to listen to music, on your food packaging, on your vehicle ... on just about everything. If you are this easily distracted, then perhaps you should find out about taking some meds.
Plus its an advertising scheme to boost sales for the engine.
And there is a problem with that? All logos are a form of advertising for the company that makes the product. That Nike swoosh does the same thing on the side of someone's shoe. So does that Chevrolet emblem on the back of someone's Camaro. I fire up a modern game and am hit with several logos right from the get go. It does not matter if it is a game made with the Unreal engine or id's latest and greatest, the game engine will be advertised via it's logo. They are all doing the same thing: pushing their product.
I see money is not enough for such companies! They obviously want more.... *shaking head*
Hello? What planet do you live on? The entire purpose of a company is to ... gasp ... make money. That's what they are in business to do. In order to make money, they need to increase sales. This means that people need to be aware that their product exists. A logo at the beginning of a game does just that. If sales of the engine continues then so does development. And continued development benefits all that use the product.