The problem is: Most people don't do that, especially new computer users. (Or, these days, people who are used to web apps, which don't use command-S.) They do

The problem is: Most people don't do that, especially new computer users. (Or, these days, people who are used to web apps, which don't use command-S.) They don't learn until they've been burned, probably quite badly. If the computer doesn't HAVE to burn them in the first place, why should it?