Range indicator with Xerath's Ultimate.

Could we please get an explanation of why when using Xerath's R with smart cast and range indicators, why can we not check the range without casting the spell? It seems it would be so simple to make it cast upon button release. Why does this spell operate differently than nearly all other spells? For many of us smart cast with range indicator users, this is insanely frustrating and completely takes away from the flow of his gameplay. Why are we forced to mouse over his R to check range? This defeats the entire purpose of using range indicators. I'd simply like to know if this was an intentional decision? Were you simply trying to make his Ultimate more challenging to use? Or was this simply an oversight. I want to play Xerath more, but this issue drives me nuts.