That's because it very clearly is. The shooter livestreamed his murder spree, and linked to his lengthy racist screed. Other investigations quickly identified other content indicating racial animus associated with that account name that will require some verification.
This attack was very clearly racially motivated. How do you think CNN should have headlined it: "Firearms discharge inside Buffalo grocery causes some harm". Come on.
Because there is no evidence that that attack was racially motivated. From what I recall, the suspect was involved in some other violent confrontation which he fled from in the direction of the Waukesha downtown with out realizing the streets were blocked and when he got to the police barriers at the parade he made his dumbest mistake of the night -- he drove past them and into the parade route. Of course the people he injured were mostly white, who else would you expect at the "Waukesha Holiday Parade"?
He'll pay for the harm he caused and his recklessness, but there is no evidence it was premeditated or racially motivated. The Buffalo shooter is the opposite. He left live evidence of his plans and motivation.