It's not just 'more time to kick the can', which still implies that not trimming debt immediately is irresponsible.
If you trim debt by a little and hurt GDP growth by a little, you wind up with the same ratio you had before. If you trim debt in a way that really hurts GDP, you'll likely increase the debt:GDP ratio.
The original paper implied that we'd wind up in a spiral of shrinking GDP, increasing that ratio, shrinking the GDP more, and so on. But it turns out it was complete bullshit.
If you trim debt by a little and hurt GDP growth by a little, you wind up with the same ratio you had before. If you trim debt in a way that really hurts GDP, you'll likely increase the debt:GDP ratio.
The original paper implied that we'd wind up in a spiral of shrinking GDP, increasing that ratio, shrinking the GDP more, and so on. But it turns out it was complete bullshit.