Question: What was the man who wrote the lyrics of "Last Night When We Were Young" an ardent critic of?

Context articles: Remember Last Night?
Yip Harburg
Last Night a DJ Saved My Life (book)
Roger Ferris
About Last Night (1986 film)
Last Night When We Were Young
Thomas Trotter (physician)
Claude Liauzu
Napoleone Colajanni
R. Eugene Pincham

Remember Last Night?
 is a 1935 American mystery comedy film directed by James Whale.
 The film, based on the novel "The Hangover Murders", is about the investigation of the murder of one of a group of friends.
 The survivors are unable to recall the events of the night of the murder because they were all too drunk.
 "Remember Last Night?"
 features an ensemble cast headed by Edward Arnold, Constance Cummings, and Robert Young.
Edgar Yipsel "Yip" Harburg (born Isidore Hochberg, Yiddish: איסידור הוכברג‎ ; April 8, 1896 – March 5, 1981) was an American popular song lyricist who worked with many well-known composers.
 He wrote the lyrics to the standards "Brother, Can You Spare a Dime?
" (with Jay Gorney), "April in Paris," and "It's Only a Paper Moon," as well as all of the songs in "The Wizard of Oz", including "Over the Rainbow."
 He was known for the social commentary of his lyrics, as well as his liberal sensibilities.
 He championed racial and gender equality and union politics.
 He also was an ardent critic of religion.
Last Night a DJ Saved My Life is a book written by Bill Brewster and Frank Broughton about the history of DJing published in 1999.
 A compilation album of the same name was released with the book.
 The album contains various clips ranging from 1970s reggae to Handel's "Largo", the first song to reach radio airwaves, in 1906.
 The book takes its name from the Indeep single "Last Night a DJ Saved My Life."
 In 2006, The Observer named "Last Night..." #45 on their list of the greatest music books.
Roger Ferris is a British pop music composer, who wrote a Top 30 UK chart hit single in 1975 for the British band Arrows, entitled "My Last Night With You."
 The song was produced by Mickie Most on his RAK label.
 "My Last Night With You" was also a top 30 chart hit in European territories as recorded by Arrows.
About Last Night (styled as About Last Night...) is a 1986 American romantic comedy-drama film directed by Edward Zwick, and starring Rob Lowe and Demi Moore as Chicago yuppies who enter a committed relationship for the first time.
 The screenplay by Tim Kazurinsky and Denise DeClue is based on the 1974 David Mamet play "Sexual Perversity in Chicago".
 The film was remade as the 2014 "About Last Night" (without the ellipsis).
"Last Night When We Were Young" is a 1935 popular song composed by Harold Arlen, with lyrics by Yip Harburg.
 Arlen regarded it as the favourite of the songs that he had written.
Thomas Trotter (1760–1832) was a Scottish naval physician and author who was a leading medical reformer in the Royal Navy and an ardent critic of the slave trade.
 Trotter was born in Melrose, Roxburghshire, and studied medicine under Alexander Monro (secundus) in Edinburgh.
Claude Liauzu (April 24, 1940 in Casablanca, Morocco – May 23, 2007), was a French historian specializing in the history of colonialism.
 He was an ardent critic of the French law of February 23, 2005 of the teaching of French colonialism describing the colonialists positively.
 He was professor at the Sorbonne ().
Napoleone Colajanni (Castrogiovanni, 27 April 1847 – Castrogiovanni, 2 September 1921) was an Italian writer, journalist, criminologist, socialist and politician.
 In the 1880s he abandoned republicanism for socialism, and became Italy’s leading theoretical writer on the issue for a time.
 He has been called the father of Sicilian socialism.
 Due to the Socialist party’s discourse of Marxist class struggle, he reverted in 1894 to his original republicanism.
 Colajanni was an ardent critic of the Lombrosian school in criminology.
 In 1890 he was elected in the national Italian Chamber of Deputies and was re-elected in all subsequent parliaments until his death in September 1921.
R. Eugene Pincham (28 June 1925 – 3 April 2008) was an African-American civil rights attorney, judge of the Circuit Court of Cook County, Illinois, and justice of the Appellate Court of Illinois.
 He was also an ardent critic of the U.S. criminal justice system (also see Race Inequalities in the Criminal Justice System).
 Known for his dramatic oratory which drew on his own personal struggles and those of African Americans, and his tireless advocacy on behalf of those less able to speak for themselves, he was regarded by many in Illinois and particularly the African-American community, as a political and legal icon, and held as a role model by both blacks and whites who came behind him.