The position the Q lands is not random though. You do have control over where it lands. In the ability description, it says "The dagger always lands on the opposite side from where it struck the first target, getting there in the same amount of time regardless of how many times it bounces." So you do have control on where it lands, which is right behind the first thing hit, it's not at all close to spray and pray. And it's now 2 bounces, not 5. So it will hit the first target, bounce to two more if available, and then land behind the first target.
And I'm sorry, it's clear you're a Katarina main, but the whole point of the Assassin Update was to give assassin's more potential, as well as give other players more counter-play. Because I can tell you, it's not fun walking back to lane, and then just dead with no way to counter. That's what Riot doesn't want.
With Katarina and her Q, it's very obvious for both the player, and the opponent, to tell where her knife is going to land, and there is where the counter play is shown. If only the player knew where the Q was going to land, then the opponent would be at a huge disadvantage.