To me one of the biggest benefits of working from is the comfort level.
When you work in an office you have set hours (usually), set times to do things like eat, take a break, etc., so their isn't as much (if any) comfort with working so you usually won't be as efficient with your work.
If you work at home, you can do things at the time you want, take breaks, eat and so on, when you want without having to worry (usually), so there is more comfort in working. This can help you to be more productive, work longer and not feel as worn down, as well as many other benefits working from how can offer.
Of course, if someone is lazy and works form home then they probably won't be as effective and their earnings will be lower than if they have a good work ethic.
I personally am a workaholic and tend to always be working. I like to see my projects grow, flourish and become better and better.
There are many benefits of working at home over at a standard location/office/etc., but this is one of the more important to me.