[toomuchtodo]

Unless your offer is wildly above comparables, it’ll appraise at or above your offer price, assuming an arms length transaction.

Cash offers distort the market because they drag up prices beyond what income driven mortgage offers would.

[KirillPanov]

This assumes that it's better for bankers to decide how customers spend their income than for the customers to decide that.

Also, "income driven mortgage" is really "salary from large employer driven mortgage". For everybody else it either underestimates, breaks down badly, or both. Especially business owners. "I sign my own payroll check" is not what a banker wants to hear.