Of course it's not important to an experienced gamer. But every new gamer has to start somewhere, and for them even seemingly obvious instructions like these can be helpful. I'm a console gamer, and I know how silly it is to be told for something like the 300th time that I move with the left thumbstick, and look around with the right one. But still, there really are people who don't know, and it's not like it takes a lot of my time. The instructions are there and gone, and if they help someone then they're not so bad.