Board Game Arena

Never wanted to go there.
Why would I exchange things when i can get resources for free??

Is it bad?

I mean, it's not a place you initially target, but depending on the situation you find yourself in, it can sometimes be your best move, especially late in the game.

It seems so, and I'm not sure I've ever gone there either, but:

imports are not easy to come by, and the customs board offers a lot of points. Money might not be easy to come by either, or rather a lot of it, you may have (or want to get) excess goods and can leverage that for something good here. Buy a lot more stuff at the exchange. The Bonus5 is always good to get, anywhere.
And maybe flexibility, just to complete the orders without obtaining just the right amount of goods. exchange what you need here.

Maybe just because I play not enough games, so I haven't find a situation like that.
Even if I have money, I always buy store/trading company first.
And for some games, I even have too many import goods lol, so I never wanted to buy one.
I'll play more games and check if i change my mind.

It was situational, but the situation I was in worked great for it. I had 4 coins and then did a 5 power action at the bank to increase to 9 coins and then I did a 5 power action in Chinatown to trade 4 copper and 1 tea for 9 coins. That gave me a total of 18 coins. The next turn, I went to the employment agency and did a 4 power action to get my last 3 trading houses by spending all 18 of those coins. 3 turns later, I had gained 40+ victory points by taking turns at Customs and the Church and placing my trading houses. This ended the game with me shooting tremendously into the lead.

Chinatown is very situational, in my experience — sometimes it really is the best option, although I think if the number of trades you could perform were increased it would be more balanced. I recall a recent game where I used Chinatown: two of the achievements were obtaining 5 copper and 10 yen, and I obtained the copper then sold it at Chinatown to get 10 yen. (I then exchanged most of it back into resources to fulfill orders.)