The "scandal around depression quest" is a bunch of lurid sexism, nothing more [1]. And "white knight" is a term invented by Redditors and not used by intelligent people. It may surprise you that plenty of men don't think of ourselves as part of some kind of "team man" fraternity where we have to stick up for "our side", and can't object to harassment of women, just as women also do.
There are indeed intelligent Redditors. However, people who use the phrase "white knights" are at best seriously misguided, and usually not among the intelligent subset. It's just a slur, not anything with content, like calling someone who acts in a way you deem insufficiently masculine a "pansy" or "fag".
[1] a bit more discussion, https://news.ycombinator.com/item?id=8267425