Do people really not back up their files regularly?

I would assume that a huge part of the reason the thieves aren't getting as much money as we'd expect is because most people back up their files at least every month or so.  Institutions should back up their files much more regularly than that.

Unless there's very significant new sensitive information that needs decrypting, there's not much reason for people to pay such a big ransom.  If it was $20 instead, I would probably pay it anyway, but there's really no point.