Where I came from it's the right wings, who wants you believe antifa is a criminal organisation which is far more extremist and radical than themselves.
This is just propaganda. Sure leftists use the term "antifa" more than the average not extremist people but this has nothing to do with the fact, that everyone who is against fascism is an antifa.
tl;dr: Sorting the "antifa" wording to the "baddies" is rightwing propaganda.