I picked "other" in the poll, because I don't think it's necessarily either good or bad to be oblivious to racial stereotypes. As you explored in the post I quoted, that could mean a lot of different things, some of which are bad, some of which are not. I'll add another wrinkle:
I was watching a comedy special by a guy named Jim Jeffries recently. And as part of his routine, he was telling a story about being on a plane and getting into a contentious argument with this big black guy sitting next to him. The black guy, who had the aisle seat, was taking the inside armrest that under normal rules of plane etiquette typically belongs to the guy in the middle seat (in this case Jim Jeffries). Eventually the flight attendant comes over and decides to split these guys up. Since the big black guy was more in the wrong, she told him he needed to find another seat somewhere further back in the plane. At this point Jim - who is Australian - stands up and shouts triumphantly "get to the back of the plane!"
To a black man. On a US flight.
Now, most of the people on the plane hadn't really heard the altercation, but surely did hear a white dude loudly telling a black man to get to the back of the plane. This did not sit well with the other passengers. Jim, being Australian, didn't realize what he'd done initially. So was it better that Jim didn't really realize how racist that sounded? Personally I have no idea. But it was damn funny.