What is so special about the water-energy-food nexus?

In an article with this title Dennis Wichelns describes connections across policy domains as being helpful, but also argues that 'the focus on water, energy and food is discretionary and limiting'.

In a similar vein I have argued for some time that the shift to so-called nexus thinking is conceptually and methodologically vacuous - we would be much better to refocus on, and reinvest in, systems thinking in practice.