Why does Tiresias say the men and Odysseus are having such a hard time at sea in The Odyssey?

In Book XI, Tiresias tells Odysseus that he is having such a hard time at sea because Poseidon, god of the sea, hates him. This hatred is born of the injury Odysseus has done to his son Polyphemus, the Cyclops whom he blinded.

Further, while Odysseus confers with the spirit of Tiresias in the Land of the Dead, he is told that he may have more difficulties in reaching home. Even so, Tiresias informs Odysseus that if he "will curb the passions" of himself and his crew, and if he will find the "kine" [cattle] and the sturdy sheep of the Sun at Thrinakia and leave them unscathed, he can arrive safely in Ithaca. But, if Odysseus harms them, he must expect the loss of his ship and crew. And, when he does return home, he may have more obstacles to overcome, although he will avenge himself against the bold men who wrong him. After Teiresias tells Odysseus these things, he says, "Teiresias, these are the threads of destiny the gods themselves have spun." Thus, he feels encouraged and sets sail, but only after he talks with many who inhabit the Land of the Dead.