Whether intentional or unintentional, assigning a specific definition to a term that lacks a commonly accepted meaning is a conversational obstructionist strategy, a tactic broadly known as 'framing'. It is used extensively by politicians to control the narrative around socialism (think red scare, palmer raids, etc). While "social democracy" is a positive framing, it still obstruct the original statement. In this case ending up in a semantics debate or attempting to assign a different emotional message. I'm not ragging on you specifically, I just want to point out that this is a thing people do.