Well, it is YOUR opinion. That's fine. But did you play the game before being so sure of it?
As it was said above, magic, missiles and multiple attacks nullify a lot differences between encounter "levels".
A careful attack will lead you more farther and more succesfully than running head down into fights.
At RQG, every combat is dangerous. So players learn very fast to plan for them or find ways to avoid them.
It may not be your favorite kind of play. So perhaps RQG is not for you. Again, that's fine.
But for a lot of people, not having a system for balancing encounters (for now, knowing that the physical Core Rules book has been available only since a few hours) is not an issue.
And Jason has already said that Gamemaster Sourcebook will contain a full chapter about adventure design (campaign/adventure/encouter design, etc.).