Millennials Are Killing is a phrasal template used to mock various think-pieces and op-ed articles on the changing consumer habits of the Millennial generation and their allegedly negative impact on major industries and economic sectors that had once thrived during the latter half of the 20th century.
A "Millennials are Killing X" trend piece generally involves a writer from the Boomer generation noting that millennials' financial situation (high student loans, lack of available, well-paying jobs) have made millennials unwilling or unable to spend as freely as their ancestors, and that this phenomenon is hurting either a specific industry or the American economy as a whole. Backlash to the trend began in 2013, notably with the response to Time Magazine's infamous Me Me Me Generation cover. Gothamist and The New York Times published articles compiling and criticizing Boomer pieces criticizing Millennials the same year.
Over the next three years, the phrase "Millenials are killing" began appearing more often in headlines, as Millennials were blamed for killing McDonald's, the movie business, Home Depot, the napkin industry, etc. The trend spiked in popularity on June 30th, 2016, when The Economist published a tweet asking "Why aren't millennials buying diamonds?" The tweet received intense derision as users mocked the transparent trendiness of the tweet and the ignorance of the question's obvious answer: millennials don't have very much money.
The trend continued to spike throughout the summer of 2016. On August 24th, Fusion published an article linking to 47 different articles, each one accusing millennials of killing a different industry or tradition. Two days later, Twitter user @necrosofty tweeted an image showing several different headlines with the phrase "Millennials are killing" in it. The tweet, shown below, has over 2,400 retweets and 2,600 likes as of August 29th, 2016.
On August 27th, The Daily Dot published an article claiming the "Millennials are Killing" backlash had reached its peak.
On December 16th, 2016, The Wall Street Journal published an article about how consumer goods company Procter & Gamble were implementing a marketing strategy to get millennials to buy fabric softener, as fabric softener sales had been on a decades-long decline due to improved washing machine technology and millennial disinterest. This led many on Twitter to make "Millennials are Killing"-style jokes about the article. One of the more popular examples came from Buzzfeed editor Tom Gara, who gained over 2,000 retweets and 2,800 favorites (shown below).
The spread of the jokes was covered in a Twitter Moment on the 17th.
On August 11th, 2018, Philly Mag posted an article titled "How Millennials Killed Mayonnaise." The headline inspired similar jokes to other articles that claimed "Millennials are killing" an industry. User @jbouie said mayonnaise salad "rightfully" died, gaining 540 retweets and 3,200 likes (shown below, left). User @KyleKirkup posted a joke about how it was yet another "Millennials are Killing" article, gaining over 80 retweets (shown below, right).
Other Twitter users joked about the content of the article itself, which featured many personal details about the author's life and was written in very verbose prose. User @Migold pointed out a sentence wherein the author seems to imply that her daughter hates mayonnaise because she's a feminist (shown below, left). The same passage led user @amandalitman to make a Tired / Wired joke calling the article "identity condiments (shown below, right). The moment was covered by Twitter Moments.
On October 10th, 2018, Business Insider published an article reporting that American cheese had fallen out of favor with the Millennial market and was being replaced with fancier cheese. The article cites several fast food chains including Wendy's, McDonald's, and Panera that have forgone using American cheese and have switched to alternatives, resulting in higher sales. Additionally, major American cheese brands including Kraft Singles and Velveeta were projecting a fourth-straight year of sales declining. The article attributed this to generational differences between Millennials and the Boomers and Generation X, the latter two of which helped bring American cheese a cultural staple.
The article led to numerous "Millennials Are Killing" jokes on Twitter, as well as insults about American cheese. User @oneunderscore_ pointed out that every thing Millennials supposedly "killed" was bad anyway, gaining over 30 retweets and 140 likes (shown below, left). User @steverousseau jokes that Millennials should eat less cheese and eat more rich people (shown below, right).
 Twitter Moments – Millennials are now being blamed for not buying fabric softener
 Twitter Moments – 'Millennials have killed mayonnaise' take has sparked a hot debate
 Business Insider – Millennials Kill Again. The Latest Victim? American Cheese