Hypocrisy is the whole point here. The speaker lectures others about language, loyalty, honesty, addiction and gossip, then immediately shows how badly he fails at each one. The lines of judgment alternate with lines of confession: he scolds about tone while screaming profanities, demands honesty while sneaking out of a hotel with his mistress, and condemns drinking and smoking while on his second pack of the day, just two weeks out of AA.
The speaker seems to feel righteous and self-assured, though the poem clearly wants us to see through him. There's no sign he notices the contradiction. Even the gossip, "Did you hear about what's his name?", comes from the same mouth that condemns gossip.
The mood is sharp and darkly ironic, with a hint of discomfort. The final lines turn the accusation on him directly: he is "just as guilty as the rest of them." The title lands as a joke, and perhaps a warning, since the harshest critic often has the most to hide.