I can definitely understand starting over. Too much baggage from Smallville. Not to mention the episode where Ollie was dressed as a showgirl is best forgotten! It's better to start over.
Though I have no idea why they're not calling him Green Arrow. He's a well-established superhero...you don't change his name. Arrow by itself sounds dumb...you need the full name for it to sound better. Also, why Starling City and not Star City?
To avoid confusion with Green Lantern and Green Hornet? That sounds silly to us lifelong comix fans, but, trust me, my own neighbors can't keep them straight. "Well-established" is a relative term.
And do know that he's not called "Green Arrow" in the show? Maybe "Arrow" is just the title.