Trivia: When Howard knocks the duck hunter out of his boat, the hunter lets out a "Wilhelm scream."
Trivia: In Howard's apartment we see the duck version of Raiders of the Lost Ark, "Breeders of the Lost Stork" from the creators of Beaks (Jaws) and Fowl Wars (Star Wars). This is referencing executive producer George Lucas's work, as well as director/writer William Huyck. Huyck did the screenplay for The Temple of Doom as well as being an uncredited writer for Star Wars.
Answer: As she said to Howard, she believed that he was using his "outlandish" appearance to be unable to find work and collect money through unemployment. She's probably dealt with people who did the same thing and was eventually sick of it.