It's such an offensive concept, isn't it? And shuts down discussion.
"I think rich people should pay more tax." "You're just jealous."
"I think private schools should be subject to VAT."
Ah, the politics of envy."
"The grammar school system is inherently inequitable." "Jealousy again."
The first three examples that came to mind.
It completely rules out any suggestion that people can be motivated by altruism or have principles, or make choices for the greater good, rather than their own personal advantage.
And it also relieves the people saying it of any motivation to think about their own standpoint.