He clearly isn't blaming them for the shooting, but drawing attention to the fact that these events are constantly used as cudgels to attempt to take away rights they don't agree with. Some would say the people trying to prevent law abiding citizens from defending themselves because they are fearful are complete assholes of human beings. California is one of the most restrictive states in the nation for firearm ownership. Its almost like these laws only disarm people who obey the law...
For your reference, the title of BADecker's thread is "16 Shot, 3 Dead At California Garlic Festival; Shooter Still At Large," which has nothing to do with "leftists." I'm not reading the ZeroHedge version of events because I could care less about what they have to say.
Nobody is trying to "prevent law abiding citizens from defending themselves," but that's a nice man made out of straw you built there.
Its not unreasonable to ask people not to bring firearms to a garlic festival.
What BADecker is actually trying to do is deflect away from the fact that this was another mass shooting by a disgruntled white supremacist who legally purchased a military-grade weapon.
It's almost like leftists want to restrict the availability of semi-automatic firearms in order to cut down on mass shootings... how dare they.