I think Menem was more genuinely likable than you say. Many people said that he was charming and fun to be around. He loved to have a good time and did not spend all his time lecturing people and shouting. Even Madonna (who had a romantic dinner with him on a Tigre island at the time "Evita" was being filmed) said that he was seductive and charming - and that's saying a lot for a short, unattractive late middle aged man.
Yes, the AIDS denial caused deaths. Cristina's ignorant and callous comment about Diabetes could do the same -- drinking Coca-Cola and eating sugar, common among the Argentine poor, could lead to Diabetes. Cristina dismisses the disease as the domain of the rich. That was a reckless and irresponsible remark.