It might be trivial for you to backup your computer, but it isn't for most people, and most people don't do it. And, beyond the risk of data loss, people now a

It might be trivial for you to backup your computer, but it isn't for most people, and most people don't do it. And, beyond the risk of data loss, people now also have to worry about identity theft and other financial loss if they do the wrong thing on their computer. (Keeping in mind here that for most people, browser == computer.)