Only two people, apparently husband and wife, found Crawford to be threatening.
Only two people we know of from what is written above. Not everybody is going to call the police. Many assume somebody else has done so or will do so, or simply care only to get themselves out of harm's way. Perhaps it was just these two who felt concerned, or perhaps there were more. You don't know which.
Why did they find him to be threatening?
How do we know that he didn't simply find the bb gun on the floor of the toy aisle and pick it up to see whether it was real or a toy?
We don't know. We should acknowledge that. We shouldn't leap wildly to conclusions that fit our preconceived ideas, such as that black man shot always equals racism. This may or may not be a case of racist cops. It is definitely a case of people on an internet forum leaping to conclusions.