It is not a new thing in the world for people to call and campaign for the death penalty for gay people 'as punishment' for being gay, although it certainly is fairly new on the political scene in South Africa.
Previously, cooler heads had always prevailed, and the notion of state-sanctioned murder was generally supported for capital crimes, like murder - and occasionally, wished upon rapists and the like. However, recently, there's been an emerging trend where religious extremists have grown more vocal about their hatred for 'the other' and began to vocalize their desire for those whom they despise to be put to death for simply being born gay or transgender.
This is a disturbing new trend among Christians, even those fanatical fundamentalists or literalists who for years restricted their efforts to pressing religious and social institutions and pressurizing government into making life as difficult for anyone who dared to deviate from the cisgender norms they held so dear.
Their hatred for those who differ from themselves overflows and overrules common sense, logic and compassion for fellow human beings, and I can only attribute its arrival here to the heavy influence of the American religious right groupings who have overrun the US Republican Party, using the gay community as a scapegoat and rallying point to try and institute a theocracy in that country over the past 8 years - and certainly the dangers of mixing religion with politics can be seen in this. For many years, right wing fundamentalist "missionaries" have been coming to SA and assisting these groups under the guise of "church planting". The same has happened in other African countries, such as Uganda - and, well, we can see the culmination of those efforts for what they've delivered - in the form of the "Kill the Gays Bill".