https://en.wikipedia.org/wiki/Social_justice_warrior
he accusation of being an SJW carries implications of pursuing personal validation rather than any deep-seated conviction,[4] and being engaged in disingenuous social justice arguments or activism to raise personal reputation.[5]
The phrase originated in the late 20th century as a neutral or positive term for people engaged in social justice activism.[1] In 2011 when the term first appeared on Twitter it changed from a primarily positive term to an overwhelmingly negative one.[1] During the Gamergate controversy, the negative connotation gained increased use, and was particularly aimed at those espousing views adhering to social liberalism, cultural inclusiveness, or feminism, as well as views deemed to be "politically correct".[1][2]
The term has entered popular culture, including a parody role-playing video game released in 2014 titled Social Justice Warriors.
It's actually the definition. There is a difference between seeing Social Justice vs a Social Justice Warrior. Think of Keyboard Warrior, Internet Warriors (Think of White Knights) or Ultimate Warrior--the addition of the word "Warrior" is used in a condescending tone.