The very beginning. "If white men are so afraid" is the antithesis of her latter point which is "white men aren't afraid" and insinuates they don't stop talking or are generally just more abundant. Even if it's not directly insulting, it's a generalization based on race (and sex) that pushes away people who happen to be white and male but also feel their voice doesn't matter.
I'm just trying to be helpful in pointing out that it's ineffective to become the monster you're fighting. I'd like racism, sexism, all of it to be extinguished and I think things even like the community rule of "only women can post" is severely detrimental to meaningful change. We must choose our responses more carefully so as not to grant the assumption that black and white are opposites no more than men and women are opposites.
There's far too much division online that doesn't exist nearly as much when we step away. We need to be reminded of that more often.
Make the point that individuals are the ones who are racist, not the demographic. People aren't racist/sexist because they're white/male, so making a claim against white/male people is ineffective. However, individuals who identify as Nazis, are racist, because the group itself is racist.
It leaves less room for "oh they're just racist misandrists targeting us" by reframing what you're saying. The critique isn't the problem but the manner in dispensing it which gives the opposition fuel to "uno reverse" the situation.
She insinuated she hears a lot of white men and made no attempt to specify what kinds of white men, only that she hears them often. Generalizing isn't bad in itself, but targeting characteristics that can't be changed for the sake of a counterpoint, is. Someone can't choose to be a man or white, so rather than allow the opposition to make it about either, reframe it into what it is. Racism, sexism, etc.
It seems pedantic but you don't want to appear to be the enemy they paint you as. You don't want to use the language they'll benefit from, no matter how right you are.