Well it all depends on the wife/husband. If s/he is earning, and agrees to give you a runway (say 3 years of you not having to pull your financial weight), you essentially get 3 years in which to get to a higher level of profitability. Of course, this all depends on your spouse's career and willingness to enter this, but I know of many marriages that have gone through intertemporal sharing of financial responsibilities.
A minimal profitability trajectory seems to imply minimized costs. A family and mortgage means added costs, so I imagine you'd have to offset that with added revenues. Wives are capable of earning an income, for instance, while mortgages are usually tied to property ownership, which in itself has income opportunities (renting unused bedrooms, or in extreme cases, moving to a place where you're paying less rent than you're collecting from the house) and, once the mortgage is paid off, the potential to reduce recurring housing costs.
Being single and without financial obligations is an optimal situation, but not the only survivable situation. As you can see from some of my ideas though, being single also gives you the latitude to make crazy lifestyle changes without anyone else having to be happy with it :)
I'd like to shake the sense that having a wife and kids and a mortgage precludes participation in a minimal profitability trajectory.