The men ignore Odysseus in the Odyssey because they want to party. They face terrible consequences as a result. What does this say about Greek attitudes and values?

When Odysseus is disguised as an old beggar, the suitors treat him terribly. However, Greek culture requires them to treat people who require food and drink, even lodging, kindly. Greeks believed in something called xenia, sort of a really enhanced level of hospitality, and most felt there was a religious imperative to offer hospitality to those who needed it, as those individuals were actually under the purview of Zeus. Thus, one honored Zeus when one offered xenia to others.
It is actually this hospitality which the suitors abuse by remaining for so long in Odysseus's house, eating his food and drinking his wine; the other side of the guest-host relationship requires that the guest not take advantage of the host's generosity. However, when given the opportunity to offer xenia to someone else—someone who appears to be in far more need than they are—they laugh at Odysseus and mock him, and they even set up a fight between him and another beggar. The fact that they face such terrible consequences for their behavior shows how much the Greeks truly did value xenia—hospitality and the guest-host relationship. That the suitors took advantage of their host and then failed to offer hospitality to others makes for a double punishment.