(snark)
Seller wants a stuck-ee, err investor, for the mortgage and to be able to pay what they want, when they want.. living free if they want in the place they can’t afford or don’t want to pay for. Seller is hoping to continue living free by having a mortgage stuck-ee, err investor, pick up the mortgage, thus preventing foreclosure, with the sellers (aka deadbeats) still able to live in the property.
(/snark)

If an investor picks this up, they may have to prepare for dealing with the BK trick that renters/leasers do to prevent eviction.