You forgot about rioters. I don't think anyone here claimed that looters are alt-left or someone with a strong ideology behind it. Here we agree.
But rioters are 99% the Left, as well as those who condone, enable, finance, and provide political, legal, academic and media support (for rioters and looters).
As a liberal, I agree that a very large percentage of the people involved in the riots, if they have any political identity at all, would be on the left. Most of the people involved in the actual riots (as opposed to peaceful demonstrations) were motivated by anger about police killing of unarmed black men, greed (the looters) or mental instability (violence for the sake of violence.) The alt-right generally hasn't been involved in what you'd call riots, but rather in threatening, heavily-armed demonstrations as the one inside the Michigan capitol, plots to kidnap a governor, street murders in Wisconsin, neo-Nazi marches in Virginia, etc. Does any reasonable person think that carrying a .223 black rifle with a 30-round banana mag to a political event is done with no thought of intimidation? I think there was more than enough craziness on both sides. Did we see that during Carter Years? The Reagan years? The Bush I years? The Clinton years? The Bush II years? The Obama years? The Trump years? Oh, wait...