Yes it is an ambiguous statement come to think of it. There are also at least two buried premises.
1) Everyone should contribute to the work of maintaining and improving the world.
2) (Apparently) There is a finite amount of this world maintaining/improving work as evidenced by the fact that some people cannot find work.
(Original statement rephrased)
3) If there is not enough work to go around then those who are working, are working too much.