It's assuming you will be fine with 30K/year over the next 40 years that is not reasonable.
So many things can change or go wrong and you end up needing more than that (exactly what happened here). If this happens relatively early and you are in an in demand job market, then it's not too bad. But if you haven't been working for the last 10 years and you are in a not super in demand market, you are in for a pretty bad time.
