Honestly, I see the collapse of fiat to be extremely unlikely and if it did come about, lead would become the currency of choice if you catch my drift. So that's not something I believe to be a good catalyst for Bitcoin to succeed nor is it something I would wish for.

The other reasons are what I would consider as more likely and why I posed this question to begin with. These "other" reasons need to be compelling enough for the masses to really adopt Bitcoin and I don't think all of these "other" reasons combined will matter if the lay man can lose everything in the blink of an eye due to a simple mistake.