The thing I don't get about threads like that are the people who say, "If white people did [X] it would be racist..." but the situations are never equivalent. Like, why would a white person go out of their way to shop at white owned businesses when most businesses are white owned?
There's a few reasons.
A lack of racial identity to properly understand and empathy the context of racial communities. There's also a general lack of historical knowledge of the racist policy legacy and wealth distribution.
The worst offender is white/ignorant people co-opting the term racism as a catch all. Black people supporting black businesses. Racism. Women supporting women business. Sexism. Gays supporting gay business. Homophobia..wait...err. Wait until heterosexuals figure a way to co-op homophobic.
It's a subtle way to take away and dilute the meaning of the word. Reduce the acknowledge of it's existence in our institutional apparatus. Like Devolution says, it's a false equivalency and a harmful one. Puts in perspective how much farther race relations needs to go in America.
I'd still encourage you to participate in these threads. Else, how would folks even begin to understand.