Hmm... the worldly and the spiritual are not separate spheres but impact each other, interpenetrate each other in myriad ways.
For instance, the vast majority of the people in the world, due to poverty and warfare, have no chance and no opportunity to discover the dhamma and practice it. We, who are blessed with both, can do something to remedy this imbalance and perhaps this is what motivates some Bhikkus to act. They help not only by translating the Tipitaka for the likes of us, but addressing the needs of those who are struggling to survive, so that they too have a chance of liberation.
The Buddha's priority was to establish a Sangha and lay a solid foundation in Dhamma, and yet he also got involved in "worldly matters" and politics, did he not, mediating between royals, trying to stave off wars?
"Cherish all beings" means different things to different people, in the way they actualise this, but actively contributing to the welfare of all, seems to me to be within the scope.
I guess I am struggling to comprehend the seemingly narrow notion of what a monk "should" and "should not do" here...