You can't be homophobic without not liking gays. There isn't a line to deliver that will suddenly make you homophobic. [...] You're definitely not being sexist when you use a gendered insult.
I'm not saying you are in and of yourself homophobic or sexist or whatever. It is possible to act homophobic without being homophobic. When you call someone a faggot, even if you're Louis CK himself, you're doing something that is homophobic. I'm sure Loius CK is not himself a homophobe, I'm sure one of his best friends, as featured on the show, is gay, but as that very man explains to him, it's still a hurtful and homophobic thing to say. Similarly, when you call someone a pussy, you are absolutely being sexist. What is a pussy? It's a vagina. Why does it mean when you call a man a pussy? You're calling him weak, or cowardly. You're intrinsically linking femininity with weakness, the same way calling someone a dick links having a penis with being a boorish jerk. Even the language you use to refute this claim implies that you know I'm right.
The claim itself bothers me because it implies that the people who came up with it and the ones who repeat it haven't even thought about it at all.
Yes, I'm sure they did think about it, which is why they use it that way.
No chain in the link said 'Oh wait, swear words have very little to do with the meaning of the word.'
Correct, I'm sure most links in that chair were aware of the meaning of what they were saying.
If a woman had worn that shirt, would she be sexist against women?
Yes, she would be perpetuating a workplace that is hostile to women.
What if she dressed like one of the people on the shirt?
Then she would probably be sent home because that would be a ridiculous outfit to wear on such an occasion, similar to the man showing up in swim trunks. This is just a ridiculous question to even ask.
If his wife got it as a gag gift, and he thought he would wear it to diffuse tension on the most tense day of his career, is he sexist now?
Yes, it is still an inappropriate thing to wear to the workplace.
What I am trying to explain is that your intentions may be all be very well and good, but the road to hell etc etc. You are not necessarily "a sexist" or "a racist" or "a homophobe" if you do offensive things. It isn't black and white like that. There is an endless gray area of sexism and racism and homphobia. It would surely be easier to live in a world where you can just casually tell a racist or sexist joke and turn to the black lady standing next to you and say, "oh sorry Sarah, I didn't mean it about you, it was just a joke!" But unfortunately it doesn't work like that.