"If Lena Dunham is being accused of being racist by omission, by extension, why do you not have disabled women on there? Trans-women? But it's about girls - spoilt, white girls in Manhattan," says Caitlin.
Talking to HuffPostLive last week, the columnist and author explained why she had reacted so strongly to her critics on Twitter, who asked why she hadn't put the equality question to Lena Dunham during a recent interview for the Times magazine.
"I was not aware of what had been happening in the US, that a lot of people had been accusing her of being racist for not having people of colour on 'Girls'," Caitlin explained.
The British writer explained that she had got "huffy" when "lots of US feminists" had contacted her on Twitter, complaining that she'd not asked Lena to justify not having a more mixed lead cast in her hit show.
"These were white, 18-year-old sociology students," described Caitlin, whose reaction she described as. "Don't tell me how to interview someone, I've been doing this job a long time, young girls."
"My response was, I don't give a shit if she doesn't have people of colour on her show," continued Caitlin.
"If you're going to say someone is racist, simply by not tackling a subject, that's an argument we need to have, because that's not what I believe.
"Do I think the entertainment industry is incredibly racist, marginalises people to the point where they are under-represented and the world looks unreal? Then yes.
"But I don't believe you're racist by omission, I can't see any truth or logic in that.
"Lena's just trying to make a funny show, make some political points and express herself. I can't remember any male artist being faced with this level of scrutiny. Has she let these people down? Those people down? She's 25 years old, making a TV show."
WATCH Caitlin's full interview on HuffPostLive above. Do you agree with her defence of Lena Dunham? Share your thoughts below...