Showing gun stats for the US as a whole is misleading and unhelpful IMO, it's such a huge place with massive differences between areas.
There are places in the US where gun crime and death rates are right up there with the worse countries in the world like Guatemala, some are even higher - Baltimore and Chicago for instance (fun fact, the top cities for crime in the US are all long-time democrat controlled - they have no solution to this, they are part of the problem).
Is the US top for mass shootings? No, not by a long way - does that mean some things shouldn't change and there isn't a problem? Of course not because there is definitely some issue.
There's certainly a problem in the US, but anyone who thinks they can solve it by simply "banning guns" is extremely naive and not serious about looking for a genuine workable solution.
I suspect that the sad truth is that many who woke up to this news and found it was a white guy were secretly "happy" because it gave them an excuse to claim Trump caused it. The leftist Warren supporter who did the follow-up shooting was an inconvenience that they now tip-toe around.
We're still waiting for the left to condemn and disavow that violence ...