If you grew up with the filth and ostracizing that came at BG because she was tall and had a deep voice, and if it followed you into every gym you played in, and onto every court you played on from at least some of the players. And then if many refs discounted the blatant physical assault on you during play because you were bigger, you might just occasionally lash out as a young person still learning their way. That there is only one recorded instance of that happening 7 years ago is pretty impressive in terms of BGs self control.
On the domestic abuse - two friends getting into a fight (male/male or female/female) is not an uncommon occurrence and nobody cares and society doesn't get into a twist over the 'violence' as long as no serious injury occurred. If it is men, its just boys will be boys, if its women, it gets labeled 'cat-fight' and the video gets millions of 'hits' on the internet. But turn it into a 'same sex couple' and it immediately becomes 'domestic abuse' and everyone wants punishment and to keep it alive, and label one of the two participants as the abuser - Johnson and Griner are not that physically dissimilar and both are elite athletes - this is not a 250 pound muscle man beating on a 150 pound weakling or a 120 pound woman.
As an aside - I was the first kid in my town and age group to have long hair - the abuse I got was pretty amazing from both age group and folks a lot older than me, and at a young age I had a really hard time handling it - and it was a personal choice I had made. I cannot imagine what it must be like for minority kids, or for the physically non-conforming, or for the mentally non-conforming kids who have no choice in the matter. It was ugly for me, it must be ten times worse for them.