Why cant the national govt just print more money to pay off debts and fund programs?

Printing more money means higher the inflation (means too much money chasing too few goods) and eventually money's purchasing power ( Price rising is nothing but fall in value of money: means with the same amount of money you will be able to buy less) will be reduced so in any case it will never make people rich unless you print money by yourself and invest first in the market to acquire resources which is illegal and called counterfeiting of money.