You're right, it's the point of the spell.
I'm saying it's a bad spell,
because that's a bad point.
Arcane Eye gives one player the spotlight, and the gameplay looks like one of two ways:
Option 1:
- DM: Okay, you see a long hallway, with one door at the far end, a hole in the wall on the left, and a door on the right.
- Player with Arcane Eye: Okay, I go through the door on the right. Through the key hole.
- DM: You see x, y, z, plus a, b, c.
- Arcane Eye: Okay, now the hole on the left.
- DM: You see a trap. Also d, e, f.
- Arcane Eye: Nice. Now the door in the center.
- DM: [to the rest of the party: "yeah, go ahead and grab some snacks. We'll be here awhile"]. This looks like an armory. You see g, h, and i. Opposite this room are two more doors...
ad infinitum until the player gets bored, the party (or the DM) revolts, or the dungeon is fully mapped out.
Option 2:
- DM: not this again. Look, here's the map. Let's just say you know where everything is. Let's move on.
Fundamentally, it's a spell that encourages boring gameplay. The fact that boring gameplay 'is the point' doesn't make it any better.