Where would the money be coming from to pay these unproductive people? Nobody trades value for nothing. In a free market those who are unproductive really only hurt themselves. When the government forces the productive members to pay the unproductive it's a drain on their savings, as well as a disincentive to bother saving in the first place. The more unproductive members there are, the greater the burden on everyone else. This a huge reason the gov. is in debt, it's because of the expanding welfare state and bureaucracy that goes with it. All of this results in a system with increasing numbers of people living off the backs of the productive. The load will simply become to heavy.
Printing new currency and giving it to unproductive people does nothing to help this. It doesn't matter if they spend it on "hi-tech shit" and real investment. That currency is simply counterfeit bills that causes price inflation and hurts savers. Printing currency is great a great tool for expanding government power (welfare, warfare, bureaucracy) i.e. wastefulness and making the politicians look like heroes who can promise people everything.
Ok. Let's imagine a situation when U.S. budget is in balance. There are several million unemployed. The economy operates at below full capacity. The the gov't decides to implement a program called "Ditches for cash". It spends about 100 billion dollars a year to employ somewhere between 3 and 4 million unemployed people.
What do we have then? Disposable incomes in the economy increase by $100 billion, translating into increased spending, which increases capacity utilization and employment.
Because of increased taxes collection, the actual deficit is below $100 billion, let's say $70 billion. (Actually, if no money of these $100 billion is saved by the private sector, deficit will be zero) These $70 bln will be added to the private sector's net savings.
What's wrong here, besides the fact that this kind of work is unproductive? Anyways it not necessarily needs to be digging ditches, it might be some kind of infrastructural projects. Losing human capital is no better than doing unproductive work.
First, let's skip the economy-is-operating-below-capacity scenario because if you put people to work doing nothing, then the economy is still operating below capacity even though everyone is "working".
The root of what you are suggesting is that the Fed prints $100 billion and just gives it to everyone.
Ok, why only $100 billion? Wouldn't $300 trillion be better? What would happen if the Fed gave every person in the U.S. $1 million? According to your logic, it would mean the end of poverty because everyone would be a millionaire.
Let's make it simpler. Instead of giving away money, let's suppose that the U.S. simply declared that $1 is now $1000. The economy would explode and everyone would have enough money to buy whatever they want, right?
Ok, I have indulged in your fantasy, now for the realism. The result would not be prosperity, the result would be inflation. Things would look great for a short period time, but then increased demand will causes prices to increase. Spending would increase, but so would prices. In the end all you will have done is devalue the currency.
If the U.S. borrows the money instead of printing it, then what you are doing is taking wealth from your children. Who is going to pay back the debt? Certainly not the ditch diggers! They aren't doing anything productive so they will always require your subsidies.