The final comparisons of stacks were against electrified and reduced consumption (author started by pointing out how to reduce overall energy use to little more than 50% of the base value). There are many easy tricks that can help with this reduction - like better home insulation, keeping heating few degrees lower, using heat pumps for air conditioning, etc. - that don't mean one has to live without hot water & computers. But people need to start implementing those measures if we are to have any chance in transitioning to a sustainable energy economy.
Convincing people to pay for the switchover is going to be a long, slow process though. And in most cases it boils down to major building renovation; people are famously reluctant to try that sort of thing.
Unless I'm missing something (always a possibility, of course) their later comparisons are all to a "green stack" that doesn't include nuclear.