The punishment for me personally would be having to restrict myself for the house. A quick trip to the zoo with two kids is easily 100€. Or a spontaneous weekend away. Or just picking up something from a restaurant. True, you don't NEED that to survive, but for me personally, it makes life worth living.
For some, it will certainly be much tighter, but for me these are things that are still possible with sensible money management even after building a house and a 35-40% burden. Let's be honest, if you refrain from spending money on clothes, decorations, or electronic junk, almost everyone still has enough money for the zoo, etc. The problem is that everyone wants everything and few have any idea how to keep fixed costs low and save. Many would do well to allocate themselves a pocket money amount they have to manage monthly and save a bit if they plan larger investments. No, then it's financed over 12-24 months at 0%. As long as the ATM keeps giving out money, everyone thinks there is still enough and the next salary will definitely come.