Even though it's only once per turn, if you play your cards right you could be getting three Treasures before the turn comes back to you
Spend 5 and then leave the rest of your mana ready for a land drop and cast
While WotC could choose to abolish the Reserved List, thats an entirely different can of worms
Theres an art to playing board wipes, but also an art in not playing too many
Its not unreasonable to think you might just draw twenty cards, right there, and if your deck contains a very unusual amount of mana, you might not be far from drawing your whole deck (especially if youve got a couple of Dakmor Salvages somewhere in the mix, making it completely deterministic that you mill your deck, fill the battlefield, and set up some graveyard kill)
It's the best of the Ninja suite of creatures by far