I think a concise way to put it is that automatically assuming a man's only reason to defend a woman is to infantilize her infantilizes her. [edit: i know you didn't use the word "infantilize", but that seems to be the gist of the term "white knighting" to me -- the accusation that someone posing as the big strong man is rescuing the weak person]
If most people in a particular population are men and a random set of people come to a woman's defense, she's mostly being defended by men. Don't read too much into it.
edit: I can't reply to you, redthrowaway, so I'll just say that I wonder what the evidence is that these guys defending Ms. Stierch deserve the term "white knight" if it's not a knee-jerk reaction to any man defending a woman. I haven't seen any evidence of "expectation of a sleazy reward" so I question the application of the term. edit2: we probably agree on this particular point. I see that you take exception to the overall rejection of the term, on the grounds that it's possible to apply it correctly. I tend to agree with tptacek that it tends to be overused and incorrectly used, and really wouldn't be unhappy if it just disappeared along with the term "butthurt." :)
For the specific type of man the phrase "white knight" applies to, the motivation isn't infantilization but rather objectification. The men engaging in that behaviour don't do so because they think the woman is in need of protection, but rather because they think being protectors in that sense is what will make women have sex with them.
Again, it's not a criticism of, or term describing, men who defend women. It's a criticism of a particular kind of man who defends women in a particular way with an expectation of a sleazy reward.
That's not to say the term isn't abused; it is. I'm not arguing with tptacek's assertion that use of the term tends to lower quality of discourse, but rather with the implied assertion that the term itself is invalid or in some way offensive. As I said in my original comment, it fairly specifically describes a particular phenomenon, and if it didn't exist some other term would be invented to take its place.
I've been accused of being a white knight and been told that certain opinions I hold are held only because they will enable me to sleep with feminist women.
Strangely enough, the sort of person who says this will also happily engage in gutter-level homophobic abuse when they find out that I really have no interest in sleeping with women, feminist or otherwise.
God forbid that I could have opinions formed from reasoned evaluation of evidence.
The main problem with the term "White Knighting" is it's nearly always misused as a way to dismiss someone's valid argument. It's a discussion killer, and contributes nothing at all constructive. Even if the term really does apply in a given case (and that will almost never be true), it still doesn't help to use it.
White knighting is probably a big reason women don't get into tech. Being turned off by the desperate geeks they meet from the time they're 14 to 22 probably has an impact on their decisions on what to do in life.
If most people in a particular population are men and a random set of people come to a woman's defense, she's mostly being defended by men. Don't read too much into it.
edit: I can't reply to you, redthrowaway, so I'll just say that I wonder what the evidence is that these guys defending Ms. Stierch deserve the term "white knight" if it's not a knee-jerk reaction to any man defending a woman. I haven't seen any evidence of "expectation of a sleazy reward" so I question the application of the term. edit2: we probably agree on this particular point. I see that you take exception to the overall rejection of the term, on the grounds that it's possible to apply it correctly. I tend to agree with tptacek that it tends to be overused and incorrectly used, and really wouldn't be unhappy if it just disappeared along with the term "butthurt." :)