Maybe not, but this guy sure is: https://www.axios.com/christchuch-attacks-brenton-tarrant-15...

Obviously the twitter hive-mind went too far in singling this one guy out, and SDG&E colossally fucked up in not doing basic due diligence before firing him. That doesn't change the fact though that there are people out there who do indeed use the hand sign to unironically mean exactly the things that 4chan set out to convince people that it meant. Sticking your head in the sand and pretending otherwise is nothing short of willful ignorance.