This demonstrates how bad it will be. Apparently, the male population has been decimated and seven women will want to be married to one man so that they will not have the reproach of being without children.
The reproach appears to be childlessness.
The reproach is that of being childless. From the Jewish standpoint that was not only the great sorrow, but the great shame, of womanhood, implying, as men thought, a sin of which it was the chastisement (Genesis 30:23; 1Samuel 1:6; Luke 1:25). (Ellicott's Commentary for English Readers - BibleHub.com Isaiah 4:1)
These women are willling to work to obtain their own food and clothing. Under these situations, it is unlikely that a single man would agree to take on seven wives. He would not be able to provide for them all.