I would think the point is that if nuclear costs more money, it's suggestive that it doesn't really use less resources than other options that cost less. Of course, that's not entirely true, as some of the costs for nuclear are insurance, which isn't priced particularly rationally, and of course, for human expertise, but that's arguably a far more scarce resource as are land and raw building materials - i.e. if you're using highly-skilled human brain power to design/build/run nuclear power plants, it prevents us from using that brain power to do other potentially more productive things (which might include coming up with better solutions for our environmental challenges). To be clear - I'm quite supportive of more nuclear power, but certainly not because it uses less land or resources.