Why don't people accept the open catalan?

As someone who plays the Catalan as white, and did so before Magnus made it fashionable recently, I think a lot of players dont play the open catalan as black because they dont know it well enough to feel confident going down that path. Often I see Tarrasch, Slav and Chigorin set ups, or just a plain old King's Indian. Black typically decides to go for a structure that he or she is familiar with, which is understandable. I see more closed Catalan for sure from black as opposed to Open Catalan when black decides to play into a proper Catalan.

Because most Black players at lower level know little about the Catalan opening. They play intuitively, assuming that Catalan is just a weird sideline of Queen's Gambit, so they never play dxc4 before castling.

They might also fear that dxc4 is an unfamiliar gambit. They fear if they take the pawn they would be in great trouble.

@AbhirupPal said in #1:

The open catalan is the best way to play the catalan for black. But in 80% of my games people play a semi slav structure
Hardly objective that it is best possible. But the we come to real life and notice that best move by computer/opening theory may not be the best for specific player. Open version may require more tactical awareness hence player stronger than you probably would pick that against you partly on basis that it offers them better chances to show their superiority quickly. Or they just like it.

lol everyone's talking about chess like they're GMs while I'm stuck in the >1300 blitz arenas and I don't have FIDE rating

Emotional and psychological reasons. As a lower rated player, we are not going to grab a pawn, meanwhile partly surrendering the center (giving up pawn control of e4), which throws us into a complex middle-game. We are going to sit back and wait for you to come directly at us.
Catalan development looks just enough different from other queen pawn openings to make us suspect (correctly, as in your case) that the white player knows what he is doing, and we don't.

My, my, my, said the spider to the fly, jump right ahead and you're dead.

I find it's very easy to mess up the open Catalan with Black. More memorization of lines is needed. I've lost many games in under 20 moves because I couldn't remember the correct moves, even though I've studied it quite a bit recently. The closed Catalan is passive, but safer if you don't think you'll remember the lines. Just my 2 cents, based on the way I play it. I'm not giving up on it.

@Frogster64 said in #17:

I find it's very easy to mess up the open Catalan with Black. More memorization of lines is needed. I've lost many games in under 20 moves because I couldn't remember the correct moves, even though I've studied it quite a bit recently. The closed Catalan is passive, but safer if you don't think you'll remember the lines. Just my 2 cents, based on the way I play it. I'm not giving up on it.
Do you play the open catalan or the closed?

Do you play the open catalan or the closed?

Both. It depends on when I last studied the Open Catalan.