Making the payback at marginal rates (0% for below $40k and 20% for everything above that) would largely fix this issue. If you are making around $40k per year

Making the payback at marginal rates (0% for below $40k and 20% for everything above that) would largely fix this issue. If you are making around $40k per year, you have nothing to lose; if the program doesn't improve your state in life at least you don't have to pay too much back. Non-marginal (15% of everything) plus the "you must work for us if we beat offers" theoretically could lead to them offering everyone a $40,001 per year job, essentially forcing them to work that for 2 years and incur high payback costs.