Xi's much-publicised drive against corruption has ensnared a long list of senior and junior officials including the country's former security czar Zhou Yongkang, who was sentenced to life in jail in June.
Zhou is regarded as an ally of former President Jiang Zemin, who ruled from 1989 to 2002 but is believed to have retained significant power throughout the following decade, when Hu Jintao was President.
Speculation has circulated over whether Jiang could be targeted by Xi and the party's internal investigation branch, the Central Commission for Discipline Inspection (CCDI).
Today's People's Daily commentary lambasted unnamed "retired leaders" for clinging to power and causing rifts within the party.
"Some leaders not only installed their cronies (in key positions) to create conditions for them to wield influence in future, but also wanted to intervene in the major issues of the organisation they formerly worked for, even many years after they retired," it said.
Such actions made new leaders feel that their "hands and feet" were fettered by having to work within "unnecessary concerns", it added.
Gu is an officer with the Chinese military's General Political Department, according to the website of the China Writers' Association, of which he is a member.
The People's Daily did not provide of description of Gu, although it did so for all the other contributors to its "Theory" page, which appears every weekday.
The article compared a leader's retirement to the waning temperature of a hot drink.
"The tea must cool after the guest left, otherwise it will go bad," it said. "It should become a norm that when you leave office, you leave your opinions behind."
"What if the ginger tea just wants to stay as hot as before?" asked one poster.