Hi wrong - I think felas has covered most of it particularly well.
The other point for me, is the statement made, suggests that racism isn't alive and well and an ongoing issue, nor does it find it's way into everyday life. It patently is and does.
Yes, we all know and accept that racism is bad. The problem often lies with, what people define as racism. There is still a load of bigotry about black people, and things said that are just plain racist, but because it's not outwardly vicious or antagonistic, it's not picked up on. It's all harmful and prejudicial rhetoric, nonetheless. It perpetuates myths and fallacies that black people are unable to shake off or enable them to be treated or viewed equally. For eg, many people don't think being anti-immigration is a racist stance. It is.
There's nuance, and thought processes that mean black people are at such a huge disadvantage still (even though there is a black US president, and many successful black people like Oprah, Kanye, JayZ, MLK, Beyonce, Maya Angelou etc etc). That's without the out and out racist comments, KKK stuff, violence, and police bias that is killing so many black americans. (I'm sure you've read why #alllivesmatter and #policelivesmatter is harmful to the #blacklivesmatter hashtag?)
In addition, the comparison ties in with the problem we have in the UK especially, whereby people say or do something that is racist (usually unintentionally), and when they are told that it is racist, they act as though you have injured them somehow (rather than consider their point of view or actions). Because being called racist is seemingly more of an insult than racism itself.
So to say "if you changed x word for racist word, it would be picked up on" is a) unhelpful, b) inaccurate and c) belittles racism as an ongoing struggle (even though it comes from good intentions).
I hope that helps explain my point a bit more clearly? And I haven't derailed THIS thread by making it about racism.... ? 