Because humor is a good mechanism for talking about topics we might not otherwise talk about, but should be.
By "adversarial discourse", do you mean the site or the HN comments?
Lately, I have even witnessed people complaining that most donations come from white men charities and that this is bad (with some people even suggesting they should refuse those donations to make a point), which seems completely nonsense.
How far does it have to go for these attempts to raise awareness of a problem to turn into racism themselves?
vs
> Lately, I have even witnessed people complaining that most donations come from white men charities and that this is bad
So... you complain that the website is generalising, then go on to imply that a clear outlier is also the general case?
EDIT: Instead of downvoting, why not provide your view of how this is helping anything?