I agree with this and I initially thought I saw 343's vision, to give the casual player as much info as the competitive player, but the competitive player having a slight "edge" by being able to set up for the weapons ahead of time.
Unfortunately the system is completely borked, right down to the wrong weapons appearing on the Waypoint.
Let's think of how it could have worked though. Imagine if on MLG's version of The Pit, off the initial spawn there simply was no image of the sword in the sword room. Instead, as you approached it, you saw the Plasma Pistol. (Note: you had to approach it because waypoint's appear at a shorter distance for non-power weapons in this "perfect world.")
Now, snipers appear at the towers every two minutes. So, you see them on the initial spawn in this MLG variant, and you see them right as they spawn after two minutes. The advantage for the "higher tiered" player comes in because he knew it would be there in two minutes, so perhaps he made his way over their before the "lower tiered" player and was ready for him.
That's how I pictured these ordnance waypoints working... and it's not at all how they work.
They just should have made cycling through grenades "up" on the d-pad. Honestly, this is one of the most baffling oversights to me.