Edit: TO COMMUNISTS,ANARCHISTS, OR ANYONE ELSE CALLING FOR THE OVERTHROW OF SOCIETY
THIS OBVIOUSLY ISN’T MEANT FOR YOU.
You’re asking why radical leftists reject your reformism. Who other than radical leftists are going to give you an actual answer instead of a pat on the back?
Anyway the answer is liberalism is far more violent, it just exports the violence overseas and commits it at an industrialised level. The infamous “Terror” in France only killed a few thousand people - the Iraq war killed over a million. While millions were killed in the cultural revolution, hundreds of millions were killed by the British Raj. Revolutionary violence is in fact far less violent than regular capitalism, so you’re hated for supporting its continuation.