Sand wrote:
the bulk of unnecessary communication (such as this site)
I wouldn't count the internet as a luxury item, because it's a valuable resource for education and social networking are very useful for people who aren't so good at communicating to others face-to-face. Plus, there's a diversity of entertainment on the internet that doesn't come at any added cost (wikipedia, youtube, etc).
In any case, I think everybody needs to entertain themselves. If you spent your entire alternating between working and being bored, and giving as much as you possibly could to charities, that would probably have a negative impact on you. You probably wouldn't be as productive or creative when you do work, and you might end up becoming depressed and losing motivation. It's certainly conceivable that if many people lived like this, and these negative consequences did occur, they might end up making less money than they would otherwise, and they would thus have less money to give away.
Really, the point is just that I doubt anybody could stand by the principle absolutely, and it might be counter-productive if we tried. Of course, having said that, we have to keep in mind that there are millions of people out there who are literally starving to death, while I'm here complaining that the fruit salad is too warm because somebody left it out the fridge.