Giving people access to healthcare and fire protection doesn't create any bad incentives. You can't 'use' healthcare for monetary gain.
Giving people food, money etc, gives people incentives to not bother working.
Also I would say that a national health service ensures that the public is 'healthy'. Which affects us all, as diseases are transmitted etc. Just as the fire services ensures fires don't spread and burn down all the houses.
The same isn't true of giving people food.