It really is creative activists trying things against the will of the people in those states that support capital punishment. I've got a complicated relationship with the death penalty, but that aside I recognize that the only way to change it is through the institutions we have which are empowered to make those changes.
Corporations are amoral. The activists found a weak point in the death penalty system -- namely, the companies which make the drugs (which is a small market to start with) and are terrified of even the remotest smidgen of public criticism.
Also, do you mean that it is Ok to kill a prisoner because it is too expensive to keep him alive?
(Yes, it's also a miscarriage of justice to wrongly execute the innocent—and to wrongly imprison the innocent, and to fail to execute those guilty of certain crimes)
And how would killing again unstab those 5 and bring them back from the dead?