Activists against the death penalty raise costs by frivolous litigation and then claim that the death penalty is too expensive. The same thing they've done with other things they don't like, e.g. nuclear power. It's circular logic.
Nice attempt at shifting the goalposts and shifting blame. And making a false equivalence with nuclear power.
Abolishionists want capital punishment abolished because capital punishment is inhumane, cruel, and morally objectionable.