If you have a family ,it will teach you how to save money for your future. But if youre single and dont have any plans for the future you will not know what is the meaning of saving if your totally have nothing.
I think for a single person it is not a problem to save money, as a single person do not need any higher amount of money for his living and so the remaining money will be saved with him, while a person with family will not be able to save any amount as the family demand nowadays is unable to fulfill by a person whose income is a normal income.
The moral was that a single person might have neither incentive nor desire to save money just because it is not a problem for him (read he has enough funds for himself and may have never been in an urgent need of money). Starting a family will surely drain your funds dry (unless you
are a millionaire already)...
While closing a family may well leave you without means of subsistence (even if you
were a millionaire before)