As a debtor, I would rather debt that can be discharged through bankruptcy, so there is incentive there to prefer this offer to that of another similar offer that doesn't include the debt transfer. In other words, there is benefit to both the borrower (a 'better' kind of debt) and lender (we sell something we might otherwise not).

Presumably because it allows buyers who would not qualify for home loans based on cash flow (impeded by student loans) to be eligible.

Or at least, that's my guess.

I know home loan standards are pretty static, so I'd guess it's to allow indebted students to qualify.

For the building company it's a 3% discount wrapped up in marketing.