"Let'em burn" with respect to "the banks" has been researched and cited as exacerbating the great depression[1].
I know there are folks legitimately concerned with moral hazard, and genuinely believe letting it all burn down would have been the better approach. I'm just glad they weren't in charge when everything went into a tail spin. I think it would have been a LOT worse for everyone.
The Automaker bailout, in hindsight, seems like it was the better call than letting them fail. If they had failed, the surviving ones would have acquired all the valuable scrap on a fire-sale, expanded to fill the void and you'd probably have more or less the same auto industry today. But in the interim, a lot of people would have lost their jobs. So that's a LOT worse for some, and I honestly can't tell who wins but on aggregate I assume it's a wash.
1 - https://www.federalreservehistory.org/essays/great_depressio...