Society punishes people for attempting to do bad things but not to the same extent.
There is also a question of evidence. It's not just that Will Smith did something bad, but that it was on live TV. There were a lot of witnesses.
John Wayne was restrained off-camera, so the Academy was able to hush it up. But we don't specifically know what he would have done if he weren't restrained. We also don't want to create perverse incentives if we treat the situations equivalently (it means that once something is initiated, there's no need to benefit to cooling down.)
That said, I'm totally fine with a three year Oscars ban for John Wayne.
How would it be a hate crime?