Do people really not back up their files regularly?
No they don't. Especially in public services where users call the IT for everything because they don't know or they don't like to do anything related to computers even though is a very stupid thing. So the most part of the day IT do lesser important tasks than it has to do. As an example ' local printer has a stuck piece of paper ' and so on.
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.
No most people are too lazy to do a regular back say after a month or more. I believe hackers they didn't target whom computer would infected from virus.
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.
I believe that $300 as a ransom is not a big amount of money for many services or institutions especially if these are located in Europe or USA or some rich countries in Asia. I don't know for the rest countries in the world.
It's $300 per computer, not per company.