I think it's because it seems to work in the long term as long as there's any kind of success waiting for them down the line. eg. If Trump wins the next election, everything up to that point is totally justified and worth it and part of the plan, etc (no matter how true or false it is, nor how lucky they may have been to have achieved the saving-their-ass success).
The cult of personality makes it so. Humanity's short memory makes it so. The media's short memory makes it so. The media's short memory is driven by the same doubling-down, new outrage distracts from previous outrage upon which it turned out our reporting was highly questionable. Layer upon layer.
The other side of the same coinj is that those who double-down and don't reach any further justifiable success rightly fade from the public consciousness (selection bias?) for the very fact they haven't done anything media-worthy since.
It feels like the double-down-at-all-costs types are increasing and spreading, but is that just because they're the ones stupidly lucky (or rich) enough to maintain a media presence?
Lastly, and related, there's always the "no news is bad news" theory. We're still discussing Elon and Trump, so they're still making the news cycle, so they're still relevant, and irrelevance makes future success (on an Elon and Trump scale) more difficult.