I understand where your coming from, however melee players can be just as cheap, like using directional ar bounce to lock up players, or ww retreats. The biggest boon though I think the arena gives, is casters can no longer run 2 football fields away to escape a melee in pursuit. However I do agree, I would like there to be a missiles only / melee only style duel.
There is an entire community of Conc, Zeal, Fury and Jab characters. Smite and WW are not even considered Melee.