When a patient has heart failure, you try to stabalize him first. You don't immediately put him on the operating table to do stomach reduction surgery in order to combat the obesity that caused heart failure.
The "stimulus" destroys jobs, it is a leech on the economy.
When a blind fat man gets depressed, you console him first. You don't immediately put him in a go-kart with a fistful of antidepressants,a bottle of gin and a sword in order to combat the lack of euphoria that caused the depression.
The government can borrow at 2.5% for 10 years. It can buy time that indivuals or banks cannot buy. If that time is used to let the economy recover a little and then make structural reforms to reduce debt, the idea can work.