Should be marketed differently
I think a big reason for the dissatisfaction with the program is that host families and au pairs have different expectations.
For host families, it should be marketed more like a high school exchange program—but for an older age group—with some childcare benefits, rather than just cheap childcare.
For au pairs, as a chance to improve English, gain childcare experience, and work abroad—not just an easy way to move to another country.
Clearer expectations on both sides would make the experience much better for everyone.