But that could take a few years, and if the place that leaving is so terrible, the wife and child may not even survive this wait.
While both staying and the journey are both risky, staying is clearly the more risky of the 2 options, otherwise no one would leave, so why would any man chose the more risky option for his wife and child than himself. In many of the oppressed countries, women are at much higher risk, due to the inherent misogyny. If a women cannot leave the house or work, how can she support herself and her child whilst her husband is making the journey, applying for asylum, finding a job, applying for a visa...
And women and children do make the journey, I think someone above posted that 20,000 children arrived by boat, so it is possible for then to make the journey.