But it is true that these kinds of unintentionally racist differences in commentary are often done by white people. Not all white people but a large enough subsection of that population to become a general problem.
Too many people are wildly overanalyzing this comic or getting needlessly insulted by it. I think your interpretation is the correct one.
Casual, unintentional racism is more of a problem than people generally realize, because they’re not even conscious of it. Racism doesn’t always show itself in overt acts of hatred or discrimination. Sometimes, a well-meaning person can say or do hurtful, insulting things because of racist assumptions they don’t know they’re making.
It's the same way with sexism. It's not always blatant "wOmAn bAd"
I'd go to a mechanic with my ex to get her car worked on and everyone only wants to talk to me. I've worked food service where our cashier was a woman and people would deliberately only talk to me. I had a pipe burst at my roommates house but because I'm the man the water service guy only wanted to talk to me.
That last one fucked with me the most cause I'm like "dude, this isn't my house"
I get what you're saying, but that's a bad argument. If a racist artist drew a black person with a bone through their nose, tats on their face, with a crack pipe in one hand and a bucket of KFC in the other, they can't hide behind "where does my art say 'All black people are like this'?"