> While a bitcoin may be worth $nnn, is that the case for 0.0005 bitcoin? It could develop that the little pieces are seen to be a liability, and people might decide they're worth less than 0.0005 * $nnn. Which creates the 'risk' you're looking for.

I'm not looking for risk. I'm pointing out that a currency that appreciates in value when you stuff it in your mattress makes you far less likely to lend it out to someone and assume the risk of default, especially at interest rates that will be attractive to someone who is going to be uncomfortable paying it off even without interest, since just paying of the original loan value (denominated in the appreciating currency) without interest will mean paying over time many times the value (in purchasing power) of the original loan over its life.