How can the Zuma trial not be in South Africa's best interest

Yesterday in the Cape Argus it was published that:

The ANC's Lindiwe Sisulu told the Cape Argus last night that the party made its representations to the NPA on February 4, arguing that Zuma's prosecution should be dropped because it was not in the best interests of the country.

So how can it not be in the interest of South Africa if there is a posibility that the next president might have over 700 corruption cases against him and he refuses to go to court. If all the other people that has been involved are convicted criminals how can this guy say he is innocent. How can it not be in the interest of South Africa if the next president is a criminal. How would he run the country?