Given the historical definition of “Socialism”, I agree with you. But since most of the actual “Socialist” parties of the world have migrated to new positions which reject totalitarian socialism, I don’t think clinging to the old definition is helpful. It certainly does not match the views of many self-labeled “Socialists”.
Before the openly totalitarian socialism espoused by the Fascists, socialism had the same basic definition as it does today. The underlying question is not one of being for or against totalitarianism, but whether “socialism” requires totalitarianism or inevitably leads to it. In my current view, socialism and corporatism both lead inevitably to totalitarianism, regardless of any official position. In that sense, the Fascists didn’t create the connection, they merely recognized it.
The modern socialists have not actually migrated to new positions, they just officially reject fascism and totalitarianism, while ignoring the underpinnings and outcomes and requirements to implement the policies they still maintain. In that sense they are a synthesis of Socialism before National Socialism and the Corporatist part of Fascism. If you were to argue that a new term should be used to identify that, I would not necessarily disagree. But when you look at the policies advocated by current-era socialist parties they accurately represent it.