I'd never consider a single mom for a mate. Which works out fine, since most single moms probably wouldn't ever consider me for a mate.
See, everyone's happy this way! ;-)
While people are usually practical when deciding to marry, the reason for marrying is different than the reason they stay together. They marry for "chemistry" and they stay together for "friendship." Most, but not all, successful marriages eventually rely on friendship to cement a life time bond.
Looked at this way, marriage has more benefits than most young people appreciate.