Well exactly, it is a borrowed money and everyone will have to pay it back in some way, for example through taxation or more likely via inflation (things will get more expensive, so people will be able to afford less). The weakest, poorest will experience the problem the most, but it will affect everyone. As I mentioned, maybe there will be some great advancement in productivity and it will not be as severe. But it is a gamble and not a wise strategy for the nation.
The debt can be written off. But it will have consequences. It means no more living on debt, because no lender will be willing to lend anymore. It will be very bad for the economy, at least in the short term (who knows how many years). However, it may lead to a more sound economy in the long term, assuming the capitalism survives.