K1 Visa Sponsor Responsibilities

I have watched the 90 day fiancé show here in the USA.  Generally somewhat interesting, and has a touch of truth in many cases, even though it is a somewhat staged reality show.  My question is this.  Manyh of the sponsors have said on the show they are responsible for the immigrant for up to 10 years.   According to the laws and policies:  "  An affidavit of support is legally enforceable; the sponsor's responsibility usually lasts until the family member or other individual either becomes a U.S. citizen, or can be credited with 40 quarters of work (usually 10 years)."  Now this seems to assume that the applicant actually works for 40 quarters or 10 years.   If the applicant never works, what happens?  If the applicant never works and never meets the 40 quarters of eligible work test, does that mean the Sponsor is on the hook forever?