Saving for retirement is an extremely sensitive subject with people in their 30s — just look at the response my article on the matter got this week.

Twitter blew up after MarketWatch tweeted about the piece, where I cite a Fidelity Investments report that suggests 35-year-olds should have twice their salary saved. Even the Huffington Post, BuzzFeed and Business Insider wrote about the backlash. Of the thousands of reactions, many made jokes but most others were defensive and angry. They talked of crippling student loan debts, having low or no income and blamed the gender wage gap.