A couple of things.
Mandela was a man who achieved some great things. He also did things wrong, and made mistakes. He was just a man. Like so many of the people who achieved a lot, he also did things that many people didn't like.
What he did do was to unite a nation that many people thought could not possibly be united. It was very possible that the apartheid South Africa had so much pent up hate that it would explode into a bloodbath.
Yet it's not just white vs black. When I talked with black people, they would tell me that there was no more hatred towards white. However, as for their Zulu/Xhosa compatriot, that was another story. There was similar feeling of English towards Boers. And then there were the people of Asian or mixed race sitting somewhere in between. One only has to look at Rwanda to see the strength of tribal loyalty and the trouble it can do. Or at Zimbabwe to see what damage the continued hate toward the former white rulers did to the country. It was impossible to have a country where the complex mix of race and feeling wouldn't continue to fester.
Considering the mix, Mandela's strong emphasis on reconciliation did a great deal towards healing the wounds. His ability to produce a government which, despite its faults, still managed to work together with people of all races, was a great achievement.
Was he tried for murder has been stated in this thread? As far as I can find out, he wasn't. His wife Winnie was tried for murder. Nelson Mandela divorced her shortly after the verdict finding her guilty, but one can't imagine that a marriage which lasted for 27 years apart was a strong one to begin with.
Was he responsible for a lot of deaths? Quite possibly. Anybody in a position like that will have to make decisions that result in deaths. He didn't openly support the struggle against AIDS until after his presidency, and that would undoubtedly have contributed to a great many deaths.
Was he a communist? He's been accused of being so for many years, and it's possible. There are very recent claims of proof that he was, but I don't know the strength of his claims. The ANC is in government in alliance with the South African Communist party, and the ANC regards itself as left wing, and this undoubtedly has contributed towards the opinion some have of him.
As far as what has been said in the forum.
Comments have been made which many disagree with. We don't remove messages based on an opinion unless they step over into the area of libel. We do however remove messages where people attack other people personally- otherwise it would just be a continual slanging match which is not helpful to anybody. If you do disagree with an opinion, please feel free to respectfully say why you disagree with that opinion. Please don't attack the person when it's the opinion which you don't like. Treat the other person with respect- if your opinion is worth holding then it's worth expressing in the same manner as you would towards a court room.