You don't need to invoke the strawman of Tumblr to conceptualize that at a first-order guess the dreadful SJW (what a terrible insult!) who's been coping with racism/sexism/homophobia/ableism for most of their life has a more insightful perspective on those issues then some dude who only reads about discrimination as something that happens to other people.

No, but the point is that a lot of people will quite happily insist "I'm not really hurting anyone", immediately after being pointed out to that their behaviour patterns do in fact hurt people. That's almost exactly what happened upthread. In many people's books, that's really not on.