I agree, having the page up/down buttons which did it.. more people would associate with it.
But with these units, your limited to the remotes, which work with the technology.. and for whatever reason the manufacturer didnt put those sorts of things in. So another button has to be used. (saves remote space by dual purpose?)
You would be surprised in what you see now a days in some remotes. We got a small TV at work here for a display. It has a coax input, so you could hook an areal for digital channels to actually tune channels on it.... BUT.. the remote? It literally just has the smart features, volume, the arrow and OK key. The ONLY channel change thing is a +/-. There is no numeric keypad, etc..