They didn't really talk about Kroll Show a whole lot, but that's alright. I've never actually seen that show, not sure what it's on, but it sounds like it could be funny.
Here's the thing, though--off the top of my head I can name a bunch of shows with an all-white main cast. Once Upon a Time, How I Met Your Mother, Bunheads, Raising Hope, The Middle, Rules of Engagement, etc.
And then there are shows like The Big Bang Theory, which literally has one character of color, and everybody forgets about him because he has no development past being an Indian stereotype.
So, yes, criticize specific instances of racism or marginalization, that's fine, but targeting one show, like Girls, instead of all these other shows, is patently ridiculous. It definitely makes me feel like the critics have an ulterior motive.