For the Header Keys (which I believe this is what the attack is going after - as that is what the password unlocks), TC does use a Salt. See [0]
And for slow hashing schemes that is a fair point, but when you're looking at file decryption, there is nothing to stop parallel attempts happening at once on different machines. Also TC does support using cascading ciphers which can help to slow it down.
Note: I'm not an expert in Cryptography by any means, but this is my current understanding.