Oh yes; I'm sure too. I'm sure it's nothing to do with people not being quite as generous lending money to people they don't know as you imply.
Erm.. the people lending are doing so in exactly the same devalued currency. What does it matter what the units are? Measure it in oz gold if you want. Measure subscription as a percentage of total value if you like. It doesn't change the fact that it's "one island's" worth of money that's being crowd-sourced.
You claim it's trivial to do so... great, I shall be happy to have my scepticism proved wrong, but you've not convinced me that my scepticism is unwarranted.
Maybe one day; bitcoin will indeed make it standard that we crowd fund our mortgages/company loans from the general public. That day is not today though.
So now the loans are big enough.
Look, the concept is a proven one, it will work with large loans just as it does now with smaller ones. Of course today it's impossible to compete with FRB therefor large are largely their domain. I mean FFS you yourself admit that we will get there one day, all you need to do is admit why we aren't getting there today. Remove the fraud out-competing the honest lending and BOOM, we're there.