|This kid is my imaginary spiritual mentor. "Yeah but WHY?"|
Calling something "childish" is the ultimate conversation-stopper: if your line of argument is deemed childish, it's game over, and you've lost. But, actually, a whole lot of this social justice thing is based on that much-derided, undeniably childish complaint: "It's not fair".
Because it's not fair that women earn less than men across the board, for example. It's also not fair that only the uterus-enabled can make babies, but there's not much we can do about that - but the pay gap? Is eminently fixable.
It's not fair that some people are discriminated against and derided and raped and murdered because they're trans. We can't go back in time and magic them into a body which fits their gender identity, but we can stop fucking them over now.
It's not fair that some people are born with a rare genetic disease and some aren't, but fixing that isn't within our purview: making sure that our buildings and toilets are accessible to them is, because holding our meetings up "just one step" isn't fucking fair.
I could go on, but you get the point, right? No, little Jimmy, life isn't fair, but there's a difference between Unfair Stuff we can't change, and Unfair Stuff we can. Saying "well, suck it up: LIFE isn't fair" is a cop-out. It isn't fair. But we can make it fairer.