I feel like the author of this never really cared to understand Singer's philosophy. It's not only focused on individual actions. Singer has written books advocating for policy change in areas such as animal experimentation. He founded a non-profit that works on inspiring public awareness for animal welfare. He campaigned against tbe Vietnam war. Let me just quote this passage from Wikipedia

Singer has criticised the United States for receiving "oil from countries run by dictators ... who pocket most of the" financial gains, thus "keeping the people in poverty." Singer believes that the wealth of these countries "should belong to the people" within them rather than their "de facto government. In paying dictators for their oil, we are in effect buying stolen goods, and helping to keep people in poverty." Singer holds that America "should be doing more to assist people in extreme poverty". He is disappointed in U.S. foreign aid policy, deeming it "a very small proportion of our GDP, less than a quarter of some other affluent nations."

The ignorance of the author also shows when he calls Singer a preference utilitarian, a position that he has backed away from almost 10 years ago.

Calling Singer a supporter of the status quo is dishonest. What the author is really trying to criticize him about is for not being communist. It is Jacobin magazine, after all. For the author, anybody that comes short of flatly rejecting capitalism is a supporter of the status quo