Answer:
Because the man worked for it.
Step-by-step explanation:
Harburg feels it is a legitimate question because it goes beyond a man just begging for alms to fend for himself. The man played a pivotal role in creating the wealth that circulates the economy, he took part in keeping the society safe, he grew up in the society and contributed his quota to seeing it better. However, now he has to wait in line to partake of a wealth he helped create. So the question goes beyond him asking for what to fend for himself with, it is also him asking for what should be his by virtue of labour.