Maybe in a literal way a knockback like that makes sense, but gameplay wise this is an offensive ultimate, not a defensive one. If you're chasing someone down and want to try to finish them with your ulti, why would you want to shoot yourself backwards as if using Caitlyn's Caliber net? What's the point of having all that range on it if it's going to penalize you for using it at a distance?
Honestly I don't see any benefit of this knockback change other than for the thematic feel of it. No one wants to blow there ultimate just to reposition especially when you already have a dash as it is.. That's not to say people can't and haven't been doing this, but is that really waht it's intended to be for now?