I've never seen it as an expectation that employers place on employees, but rather something that software developers place on themselves. The nature of the profession is that one person, by themselves, can create a great piece of software with enough time and effort. Or maybe people just want to get around to putting something into practice that they did a tutorial on a while ago. Or maybe they want to learn a new skill altogether. All these possibilities lay in front of the software developer, just a few clicks away, and it can make you feel like you have to do something.
