Rather, it is a social issue. Peachum is in charge of all of London's beggars whereas Macheath is in charge of London's thieves. Stealing Peachum's daughter is thus a social affront, an attack on Peachum's status in the London underworld. The theft of Polly will cause Peachum to openly declare war on Mac the Knife in an effort to regain his reputation. The irony of the song at the end of this scene is inherent in what has already been revealed to the audience.
Love is blamed as well.
However, these are terrible parents, hypocrites because Peachum does not want his daughter to marry even though he got married. They are lamenting the fact that Polly does not know what is good for her, as if staying with them were any better than marrying the leader of London's thieves. The songs throughout this play are important because they represent a new style of theater. Operatic in presentation, they are nonetheless bawdy, cabaret style works that invert the common perception of opera. The ballads also compete with the plot for attention, causing the audience to distance itself from the characters.