[quote=Revans Exile]
If you are at the bottom of the page and want to go to the top then click the home button on your keyboard. Anything else is a waste of time better suited to anything other than copying functions of a keyboard.
[/quote]

That's assuming everyone is browsing from a computer with a keyboard. If you're at a kiosk, have a touchscreen computer or a tablet, you may not have a keyboard. Also, some new computers (Chromebooks) don't have auxiliary keys such as the Home key. 

On-screen controls are part of device-agnostic design to ensure that every has the same ability to access the website.