THROUGH all the Employments of LifeEach Neighbour abuses his Brother;Whore and Rogue they call Husband and Wife:All Professions be-rogue one another:The Priest calls the Lawyer a Cheat,The Lawyer be-knaves the Divine:And the Statesman, because he's so great,Thinks his Trade as honest as mine. I feel like this passage embodies the
entire theme of the story. It's comical but sad. The lengths people go to obtain material or financial luxuries. The Peachum's lack of compassion for others is truly classic in this story. It symbolizes Gay's perception of people's selfishness and greed of the time, and also their abuse of power.

Both evils still lurk and thrive in today's politics. We see police officers extorting criminals, lawyers extorting criminals, lawyers extorting police officers, vice versa and etc. Today's elite operate with the same morals and code of ethics as the Peachum's did then. I call it the Bush complex. It comes in effect when a person achieves a high level of financial income and still takes from, and abuses those with less. It seems like it's not about the profit anymore it seems to be about evil.
The Peachum's personify and perpetuate the system of greed and selfishness of government. I could be reading too deep into the story but this is how I perceived it. At the time of the story's creation, Gay couldn't come right out and say "the powers that be are greedy and evil thieves", so it seems he tied it into a storyline of love and romance. Similar to how the SNL (Saturday Night Live) cast portray Bush's erroneous accusations of Saddam's WMD's. It's definitely comical but underneath the costumes and punch lines lies a serious bitter truth.
My saying goes,
if the poor steal from the poor, I guarantee the rich feed the rich. This story solidifies such a quote. The Peachum's are already financially stable, yet they seek to suck others dry and scam for more wealth.
Polly loves MacHeath so she marries him, the Peachum's so deeply hateful don't say they want her to get a divorce, they want to him jailed executed so his wealth can spread to their family. It seems the Peachum's goal is to scam the life out of others, kill them if they don't pay up, and control their surroundings. Very similar to government in a lot of ways, which is what I think Gay was subliminally inserting into this play which is why plays became more political after this one.
Backlash from the Opera
The Beggar's Opera was the first example of political satire that led to the Licensing Act of 1737. The success of the opera encouraged new writers such as Henry Fielding to begin political drama works. As a result, the theatre enjoyed a few years of political satirical works, until the Licensing Act discouraged political writing.
Political propaganda within the opera was only one issue that met the objection of the public. Dr. Thomas Herring argued that the "favorable presentation of criminals" was morally unacceptable. Critics also argued that the opera was "a debased form of entertainment," a representation of "the declining taste" of the public. The critics were correct; theatre as entertainment was changing. A venue once distinguished as a high-brow, was drawing new audience members from lower classes.51 Critics claim that this melting pot of the middle and upper classes paved the way for a decline in the integrity of art and a growing movement called Sentimentalism.-
http://www.umich.edu/~ece/student_projects/beggars_opera/theater.html#set