Eh, not really - it would be “hiding how the system works, because the system is poorly designed”.
Is it, though? How many video games have you played where you can sneak right up behind an enemy without them detecting you because their backs are turned? It's not much different, really. The main difference is you can see where to NOT walk in order to avoid them spotting you.
If I'm approaching a goblin on patrol, and I can't see the cone, I suddenly have a lot less chance of successfully stealthing because I don't really know where to step to avoid triggering him finding me. How close CAN I get while he's looking right at me? It's only really because I can see the cones that I can easily, totally avoid them spotting me and get right up behind them.
