Why openings revealed during the game?

I play 3-day games. I thought it was to aid players in learning openings. Just because the computer says it's an opening doesn't mean your opponent even knows it or is playing it.
Why should players aid during the game? That's what post-game analytics is for. Of course, they see the name of the opening and if it is unfamiliar, they have the opportunity to "learn" it during the game. It is not right.

No one. It's just cool to see the names. Some of the variations have names that are just funny to see too. The Prickly Pawn Variation comes to mind. Or the Hippo.
How many different openings (around first 10+ moves) do you think the average 1000 player knows? I don't think many. People in this level get stuck in one opening usually, well maybe a couple. But why is it that every time you want to play a rare gambit, they always know the right moves or even lines? Where does such knowledge come from? This feature isn't just for people to enjoy funny opening names. It really ruins the game.
I feel like you exaggerate little bit. Show us a single game where your 1k opponent played 10 book moves. I don't believe it happened, because it would also require 10 book moves from you too. You see, for it to work both of you would have to know the moves. If YOU do non-book move on turn 3 and change direction of the game, he's not getting book move on turn 4. It's that simple
I'm not talking exactly about book moves, but about opening lines. Even if it's the first 6 moves, it doesn't change the idea.