Dual-income families are because of equality, not poverty. When women earn nearly the same pay, it's worth it for them to work (and hire childcare) because then you can use the money to buy stuff.
When they don't work, it's because it wouldn't allow the household to buy more stuff on the margin - but rather than "spouse earns so much their income doesn't matter", it's more likely "they wouldn't earn enough to pay for the services they have to hire". Which is a bad thing.
In general? Yeah, I'm sure both factors are considered in many cases (as well as things like keeping long term career options open). But this thread was specifically about where the floor for minimum wage should be set. If it is set to a point where a couple can just afford a place to live with two workers, then the decision is by definition made based on poverty, right?
When they don't work, it's because it wouldn't allow the household to buy more stuff on the margin - but rather than "spouse earns so much their income doesn't matter", it's more likely "they wouldn't earn enough to pay for the services they have to hire". Which is a bad thing.